Sample records for nerve root displacement

  1. Nerve and Nerve Root Biomechanics

    Microsoft Academic Search

    Kristen J. Nicholson; Beth A. Winkelstein

    \\u000a Together, the relationship between the mechanical response of neural tissues and the related mechanisms of injury provide\\u000a a foundation for defining relevant thresholds for injury. The nerves and nerve roots are biologic structures with specific\\u000a and important functions, and whose response to mechanical loading can have immediate, long-lasting and widespread consequences.\\u000a In particular, when nerves or nerve roots are mechanically

  2. Massive nerve root enlargement in chronic inflammatory demyelinating polyneuropathy

    Microsoft Academic Search

    W Schady; P J Goulding; B R Lecky; R H King; C M Smith

    1996-01-01

    OBJECTIVE: To report three patients with chronic inflammatory demyelinating polyneuropathy (CIDP) presenting with symptoms suggestive of cervical (one patient) and lumbar root disease. METHODS: Nerve conduction studies, EMG, and nerve biopsy were carried out, having found the nerve roots to be very enlarged on MRI, CT myelography, and at surgery. RESULTS: Clinically, peripheral nerve thickening was slight or absent. Subsequently

  3. Paraplegia after lumbosacral nerve root block

    Microsoft Academic Search

    John K Houten; Thomas J Errico

    2002-01-01

    Background context: Lumbar nerve root blocks and epidural steroid injections are frequently employed in the management of degenerative conditions of the lumbar spine, but relatively few papers have been published that address the complications associated with these interventions. Serious complications include epidural abscess, arachnoiditis, epidural hematoma, cerebrospinal fluid fistula and hypersensitivity reaction to injectate. Although transient paraparesis has been described

  4. Reconstruction of nerve root sheaths for sacral extradural spinal meningeal cysts with spinal nerve root fibers.

    PubMed

    Sun, Jianjun; Wang, Zhenyu; Li, Zhendong; Wu, Haibo; Yen, Ruyu; Zheng, Mei; Chang, Qing; Liu, Isabelle Yisha

    2013-11-01

    This study analyzed the clinical characteristics and outcomes of sacral extradural spinal meningeal cysts with spinal nerve root fibers treated by reconstruction of the nerve root sheaths. The relationships between the cysts and spinal nerve root fibers were examined microscopically, the cysts were partially excised, and the defects were oversewn to reconstruct the nerve root sheaths. The Improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological function. Thirty-eight patients were included in this study, with a mean age of 41.4 ± 15.57 years. The mean IJOA score was 18.8 ± 1.32 preoperatively and 19.6 ± 0.65 postoperatively, which was a significant difference (t=-3.77, P=0.001). These results indicate a significant improvement in neurological function after surgery. The most significant improvement in neurological function was sensation (z=-2.86, P=0.004), followed by bowel/bladder function (z=-2.31, P=0.02). PMID:24008383

  5. Spinal root origins and innervations of the suprascapular nerve.

    PubMed

    Shin, Chuog; Lee, Seo-Eun; Yu, Kee-Hyun; Chae, Han-Kyo; Lee, Kyu-Seok

    2010-03-01

    The suprascapular nerve branches provide efferent innervation to the supraspinatus and infraspinatus muscles as well as sensory innervation to the shoulder joint. This study was carried out to verify the spinal root origins and innervations of the suprascapular nerve. Fifty samples of the suprascapular nerve taken from 37 adult Korean cadavers were used in this study. The suprascapular nerve was found to comprise the ventral rami of the C5 and C6 in 76.0% of the fifty samples; C4, C5, and C6 nerves in 18.0%; and C5 nerve in only 6.0%. The C5 nerve was consistently shown to be the largest in mean diameter and was found to be a major contributor of nerve fibers leading to the suprascapular nerve. This study shows that the main spinal component of the suprascapular nerve is C5 nerve. In most cases, the rate of the involvement of the C4 and C6 nerves (18.0 and 94.0%, respectively) with the suprascapular nerve was less than that of C5 nerve. C4 and C5 nerves were shown to contribute nerve fibers to the supraspinatus and infraspinatus muscles and to both shoulder joints, whereas C6 nerve displayed variable patterns of innervation. PMID:19937327

  6. Unrecognised displacement of mandibular molar root into the submandibular space.

    PubMed

    Nusrath, M A; Banks, R J

    2010-09-25

    We describe a case of swelling in the right submandibular and sublingual space caused by displacement of a lower second molar root in the submandibular space. This displacement was not recognised at the time of extraction. The techniques used to minimise the risk of accidental displacement of teeth and roots, during extraction are discussed. The importance of recognising this complication and methods of retrieval are highlighted. PMID:20871549

  7. Lumbar Nerve Root Occupancy in the Foramen in Achondroplasia

    Microsoft Academic Search

    Hitesh N. Modi; Seung Woo Suh; Hae-Ryong Song; Jae Hyuk Yang

    2008-01-01

    Lumbar stenosis is common in patients with achondroplasia because of narrowing of the neural canal. However, it is unclear\\u000a what causes stenosis, narrowing of the central canal or foramina. We performed a morphometric analysis of the lumbar nerve\\u000a roots and intervertebral foramen in 17 patients (170 nerve roots and foramina) with achondroplasia (eight symptomatic, nine\\u000a asymptomatic) and compared the data

  8. The diameters and number of nerve fibers in spinal nerve roots.

    PubMed

    Liu, YongTao; Zhou, XiaoJi; Ma, Jun; Ge, YingBin; Cao, Xiaojian

    2015-07-01

    Objective To investigate the anatomical and histological features of spinal nerve roots and provide base data for neuroanastomosis therapy for paraplegia. Methods Spinal nerve roots from C1 to S5 were exposed on six adult cadavers. The diameter and the number of nerve fibers of each nerve root were measured, respectively, with a caliper and image analysis software. Results As for ventral roots, the diameter of C5 (2.50 ± 0.55 mm) was the largest in cervical segments. In thoracic and lumbosacral segments, the diameter gradually increased from T11 to S1 and then decreased from S1 to S5 except L3. S1 (1.43 ± 0.16 mm) was the thickest root and S5 (0.14 ± 0.02 mm) was the thinnest one. As for dorsal roots, the diameter of C7 (4.61 ± 0.87 mm) was the largest in cervical segments. From T11 to S1, the diameter increased and then decreased gradually from S1 to S5. The diameter of dorsal roots from T1 to S5 was largest at S1 (2.95 ± 0.57 mm) and smallest at S5 (0.27 ± 0.13 mm), respectively. C7 (8467 ± 1019), T12 (6538 ± 892), L3 (9169 ± 1160), and S1 (8253 ± 1419) ventral roots contained the most nerve fibers in cervical, thoracic, lumbar, and sacral segments, respectively. Similarly, C7 (39 653 ± 8458), T1 (26 507 ± 7617), L5 (34 455 ± 2740), and S1 (41 543 ± 3036) dorsal roots, respectively, contained the most nerve fibers in their corresponding segments. Conclusion The findings in the current study provided the imperative data and may be valuable for spinal nerve root microanastomosis surgery in the paraplegic patients. PMID:24605949

  9. Proposed Classification of Auriculotemporal Nerve, Based on the Root System

    PubMed Central

    Komarnitki, Iulian; Tomczyk, Jacek; Ciszek, Bogdan; Zalewska, Marta

    2015-01-01

    The topography of the auriculotemporal nerve (ATN) root system is the main criterion of this nerve classification. Previous publications indicate that ATN may have between one and five roots. Most common is a one- or two-root variant of the nerve structure. The problem of many publications is the inconsistency of nomenclature which concerns the terms “roots”, “connecting branches”, or “branches” that are used to identify the same structures. This study was performed on 80 specimens (40 adults and 40 fetuses) to propose a classification based on: (i) the number of roots, (ii) way of root division, and (iii) configuration of interradicular fibers that form the ATN trunk. This new classification is a remedy for inconsistency of nomenclature of ATN in the infratemporal fossa. This classification system has proven beneficial when organizing all ATN variants described in previous studies and could become a helpful tool for surgeons and dentists. Examination of ATN from the infratemporal fossa of fetuses (the youngest was at 18 weeks gestational age) showed that, at that stage, the nerve is fully developed. PMID:25856464

  10. Femoral nerve transfer for treatment of brachial plexus root avulsion.

    PubMed

    Gu, Y D; Cheng, X M; Chen, D S; Zhang, G M; Xu, J G; Chen, L; Zhang, L Y; Cai, P Q

    1998-11-01

    Femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was performed to determine its protective effect on the hand intrinsic muscles. Seven cases of brachial plexus root avulsion treated from May of 1989 to October of 1991 were involved. The femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was done at the same stage of multiple neurotization. The muscular branches derived from the femoral nerve were isolated and coapted with the thenar muscle branch of the median nerve and the deep branch of the ulnar nerve. A groin flap was harvested simultaneously to form a skin-tube pedicle that covered the nerve bridge. At the second stage, when regeneration of the median and ulnar nerves was found to reach as far as the level of the wrist, the femoral nerve was divided and the muscular branches of the thenar and hypothenar muscles were anastomosed with the regenerated median and ulnar nerves. All the cases were followed up for more than 6 years. Six months after femoral nerve transfer, muscle power of the interosseous muscles and adductor pollicis recovered to MRC3, whereas that of the abductor pollicis brevis recovered to MRC1 to 2. Five cases underwent second-stage transfer. Four to five years of follow-up revealed that the muscle power of the interosseous muscles and adductor pollicis was MRC2 in one case, MRC1 in three cases, and MRC0 in one case. As for the donor area, muscle power of the quadriceps femoris reduced to M3 to 4 within 1 month after femoral nerve transfer and recovered to normal at 3 months. In conclusion, femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles has some protective effect on the hand intrinsic muscles. The outcome of the second stage, however, is not satisfactory. PMID:9810993

  11. Loss of dorsal root ganglion cells concomitant with dorsal root axon sprouting following segmental nerve lesions

    Microsoft Academic Search

    H. A. Lekan; K. Chung; Y. W. Yoon; J. M. Chung; R. E. Coggeshall

    1997-01-01

    Tight ligation of the fifth and sixth lumbar segmental nerves in the rat provides a model of neuropathic pain. We used this model to assess the changes in primary afferent input to the dorsal horn in neuropathic pain syndromes. Dorsal roots and ganglia were examined for up to 32 weeks following segmental nerve ligation. Stereologic and morphometric techniques revealed a

  12. Paraplegia after lumbosacral nerve root block: report of three cases

    Microsoft Academic Search

    John K. Houten; Thomas J. Errico

    Background context: Lumbar nerve root blocks and epidural steroid injections are frequently employed in the management of degenerative conditions of the lumbar spine, but relatively few papers have been published that address the complications associated with these interventions. Serious complications in- clude epidural abscess, arachnoiditis, epidural hematoma, cerebrospinal fluid fistula and hypersensitivity reaction to injectate. Although transient paraparesis has been

  13. Displaced retinal ganglion cells in normal frogs and those with regenerated optic nerves

    Microsoft Academic Search

    S. A. Dunlop; M. F. Humphrey; L. D. Beazley

    1992-01-01

    We have analysed the number and spatial distribution of displaced retinal ganglion cells in the frog Litoria (Hyla) moorei. A series of normal animals was compared with one in which the optic nerve was crushed and allowed to regenerate. Ganglion cells were labelled with horseradish peroxidase (HRP) applied to the optic nerve, and retinae were examined as sections or whole

  14. Characterization of a chondroitin sulfate hydrogel for nerve root regeneration

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron; Panitch, Alyssa

    2011-10-01

    Brachial plexus injury is a serious medical problem that affects many patients annually, with most cases involving damage to the nerve roots. Therefore, a chondroitin sulfate hydrogel was designed to both serve as a scaffold for regenerating root neurons and deliver neurotrophic signals. Capillary electrophoresis showed that chondroitin sulfate has a dissociation constant in the micromolar range with several common neurotrophins, and this was determined to be approximately tenfold stronger than with heparin. It was also revealed that nerve growth factor exhibits a slightly stronger affinity for hyaluronic acid than for chondroitin sulfate. However, E8 chick dorsal root ganglia cultured in the presence of nerve growth factor revealed that ganglia cultured in chondroitin sulfate scaffolds showed more robust growth than those cultured in control gels of hyaluronic acid. It is hypothesized that, despite the stronger affinity of nerve growth factor for hyaluronic acid, chondroitin sulfate serves as a better scaffold for neurite outgrowth, possibly due to inhibition of growth by hyaluronic acid chains.

  15. Infrared neural stimulation of human spinal nerve roots in vivo.

    PubMed

    Cayce, Jonathan M; Wells, Jonathon D; Malphrus, Jonathan D; Kao, Chris; Thomsen, Sharon; Tulipan, Noel B; Konrad, Peter E; Jansen, E Duco; Mahadevan-Jansen, Anita

    2015-01-01

    Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients ([Formula: see text]) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and [Formula: see text]. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at [Formula: see text] and a [Formula: see text] safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans. PMID:26157986

  16. SEVENTH CERVICAL NERVE ROOT TRANSFER FROM THE CONTRALATERAL HEALTHY SIDE FOR TREATMENT OF BRACHIAL PLEXUS ROOT AVULSION

    Microsoft Academic Search

    Y. D. GU; G. M. ZHANG; D. S. CHEN; J. G. YAN; X. M. CHENG; L. CHEN

    1992-01-01

    Cervical root nerve transfer from the contralateral side has been used for the treatment of brachial plexus root avulsion in 49 patients. Resection of C7 root from the healthy side has produced no long-term symptoms or signs. Nine patients with ten recipient nerves have been followed up for more than two years and seven have obtained a functional recovery. This

  17. Altered Median Nerve Deformation and Transverse Displacement during Wrist Movement in Patients with Carpal Tunnel Syndrome

    PubMed Central

    Wang, Yuexiang; Filius, Anika; Zhao, Chunfeng; Passe, Sandra M.; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.

    2014-01-01

    Rationale and Objectives: Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Strong pinch or grip with wrist flexion has been considered a risk factor for CTS. Studying median nerve displacement during wrist movements may provide useful information about median nerve kinematic changes in CTS patients. The purpose of this study was to evaluate the deformability and mobility of the median nerve in CTS patients compared to healthy subjects. Materials and Methods: Dynamic ultrasound images were obtained in 20 affected wrists of 13 patients with CTS. Results were compared to complementary data obtained from both wrists of 10 healthy subjects reported in a previous study. Initial and final median nerve shape and position were measured and analyzed for six defined wrist movements. The deformation ratios for each movement were defined as the median nerve area, perimeter and circularity of the final position normalized by respective values assessed in the initial position. The median nerve displacement vector and magnitude were also calculated. Results: The deformation ratio for circularity was significant less in CTS patients compared to healthy subjects during wrist flexion (P<0.05). The mean vector of median nerve displacement during wrist flexion was significantly different between CTS patients and healthy subjects (P<0.05). The displacement magnitude of the median nerve was found to be less in CTS patients compared to healthy subjects during most movements, with the exception of wrist extension with fingers extended. Conclusions: CTS Patients differ from normal subjects with regard to mobility and deformability of the median nerve. PMID:24594417

  18. Autologous nerve graft repair of different degrees of sciatic nerve defect: stress and displacement at the anastomosis in a three-dimensional fnite element simulation model

    PubMed Central

    Piao, Cheng-dong; Yang, Kun; Li, Peng; Luo, Min

    2015-01-01

    In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the magnitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the treatment. One-dimensional stretching is commonly used to measure changes in tensile stress and strain; however, the accuracy of this simple method is limited. Therefore, in the present study, we established three-dimensional finite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 finite element simulation software, we calculated the maximum stress and displacement of an anastomosis under a 5 N load in 10-, 20-, 30-, 40-mm long autologous nerve grafts. We found that maximum displacement increased with graft length, consistent with specimen force. These findings indicate that three-dimensional finite element simulation is a feasible method for analyzing stress and displacement at the anastomosis after autologous nerve grafting. PMID:26109958

  19. Autologous nerve graft repair of different degrees of sciatic nerve defect: stress and displacement at the anastomosis in a three-dimensional fnite element simulation model.

    PubMed

    Piao, Cheng-Dong; Yang, Kun; Li, Peng; Luo, Min

    2015-05-01

    In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the magnitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the treatment. One-dimensional stretching is commonly used to measure changes in tensile stress and strain; however, the accuracy of this simple method is limited. Therefore, in the present study, we established three-dimensional finite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 finite element simulation software, we calculated the maximum stress and displacement of an anastomosis under a 5 N load in 10-, 20-, 30-, 40-mm long autologous nerve grafts. We found that maximum displacement increased with graft length, consistent with specimen force. These findings indicate that three-dimensional finite element simulation is a feasible method for analyzing stress and displacement at the anastomosis after autologous nerve grafting. PMID:26109958

  20. The distal sensory nerve action potential as a diagnostic tool for the differentiation of lesions in dorsal roots and peripheral nerves

    Microsoft Academic Search

    R. Benecke; B. Conrad

    1980-01-01

    On the basis of the conception that, in preganglionic lesions, peripheral sensory nerve fibers should remain intact, the question arises whether evaluation of distal sensory nerve action potentials can be helpful in differentiating between cervical dorsal root and peripheral nerve lesions. Amplitudes of sensory nerve action potentials (SNAP) and corresponding distal sensory conduction velocities (SCV) of the median and ulnar

  1. Prolonged electrical stimulation causes no damage to sacral nerve roots in rabbits

    PubMed Central

    Yan, Peng; Yang, Xiaohong; Yang, Xiaoyu; Zheng, Weidong; Tan, Yunbing

    2014-01-01

    Previous studies have shown that, anode block electrical stimulation of the sacral nerve root can produce physiological urination and reconstruct urinary bladder function in rabbits. However, whether long-term anode block electrical stimulation causes damage to the sacral nerve root remains unclear, and needs further investigation. In this study, a complete spinal cord injury model was established in New Zealand white rabbits through T9–10 segment transection. Rabbits were given continuous electrical stimulation for a short period and then chronic stimulation for a longer period. Results showed that compared with normal rabbits, the structure of nerve cells in the anterior sacral nerve roots was unchanged in spinal cord injury rabbits after electrical stimulation. There was no significant difference in the expression of apoptosis-related proteins such as Bax, Caspase-3, and Bcl-2. Experimental findings indicate that neurons in the rabbit sacral nerve roots tolerate electrical stimulation, even after long-term anode block electrical stimulation. PMID:25206785

  2. Conjoined lumbosacral nerve roots: observations on three cases and review of the literature.

    PubMed

    Artico, M; Carloia, S; Piacentini, M; Ferretti, G; Dazzi, M; Franchitto, S; Bronzetti, E

    2006-02-01

    Lumbosacral nerve root anomalies are a rare group of congenital anatomical anomalies. Various types of anomalies of the lumbosacral nerve roots have been documented in the available international literature. Generally speaking, these anomalies may consist of a bifid, conjoined structure, of a transverse course or of a characteristic anastomized appearance. Firstly described as an incidental finding during autopsies or surgical procedures performed for lumbar disk herniations and often asymptomatic, lumbosacral nerve root anomalies have been more frequently described in the last years due to the advances made in radiological diagnosis (metrizamide myelography and CT, MRI). Our study comprised three patients with conjoined lumbosacral nerve roots, representing 0.25% of a total of 1200 patients who underwent lumbosacral CT/MRI procedures in the Addolorata Hospital and in the Service of Neuroradiology of the University of Rome "La Sapienza" during the last three years (March 2001-March 2004). We report our experience with three cases of conjoined lumbosacral nerve roots and analyze the most important literature on this topic. MR imaging is a better diagnostic procedure (in comparison to CT) for the differentiation of nerve root anomalies and, in particular, coronal sections furnish a precise definition of the profile of the conjoined/enlarged rootlets. In fact, the accurate information derived from MRI of multiple planes may be priceless for the preoperative and diagnostic evaluation of lumbosacral nerve root anomalies. PMID:16565781

  3. Primary glioblastoma of the trigeminal nerve root entry zone: case report.

    PubMed

    Breshears, Jonathan D; Ivan, Michael E; Cotter, Jennifer A; Bollen, Andrew W; Theodosopoulos, Phillip V; Berger, Mitchel S

    2015-01-01

    Gliomas of the cranial nerve root entry zone are rare clinical entities. There have been 11 reported cases in the literature, including only 2 glioblastomas. The authors report the case of a 67-year-old man who presented with isolated facial numbness and was found to have a glioblastoma involving the trigeminal nerve root entry zone. After biopsy the patient completed treatment with conformal radiation and concomitant temozolomide, and at 23 weeks after surgery he demonstrated symptom progression despite the treatment described. This is the first reported case of a glioblastoma of the trigeminal nerve root entry zone. PMID:25380115

  4. Spinal Nerve Root Haemangioblastoma Associated with Reactive Polycythemia

    PubMed Central

    Law, Eric K. C.; Lee, Ryan K. L.; Griffith, James F.; Siu, Deyond Y. W.; Ng, Ho Keung

    2014-01-01

    Haemangioblastomas are uncommon tumours that usually occur in the cerebellum and, less commonly, in the intramedullary spinal cord. The extramedullary spinal canal is an uncommon location for these tumours. Also haemangioblastoma at this site is not known to be associated with polycythemia. We present the clinical, imaging, and histological findings of an adult patient with extramedullary spinal haemangioblastoma and reactive polycythemia. Radiography and computed tomography (CT) revealed a medium-sized tumour that most likely arose from an extramedullary spinal nerve root. This tumour appeared to be slow growing as evidenced by the accompanying well-defined bony resorption with a sclerotic rim and mild neural foraminal widening. Magnetic resonance imaging revealed prominent flow voids consistent with tumoural hypervascularity. CT-guided biopsy was performed. Although preoperative angiographic embolisation was technically successful, excessive intraoperative tumour bleeding necessitated tumour debulking rather than complete tumour resection. Histology of the resected specimen revealed haemangioblastoma. Seven months postoperatively, the patients back pain and polycythemia have resolved. PMID:25431722

  5. A validated finite element analysis of nerve root stress in degenerative lumbar scoliosis

    Microsoft Academic Search

    Ho-Joong Kim; Heoung-Jae Chun; Kyoung-Tak Kang; Hwan-Mo Lee; Hak-Sun Kim; Eun-Su Moon; Jin-Oh Park; Bo-Hyun Hwang; Ju-Hyun Son; Seong-Hwan Moon

    2009-01-01

    Few studies have shown the relationship between the curve pattern and nerve root symptoms in degenerative lumbar scoliosis,\\u000a and its mechanism remains unclear. We developed a finite element model of two patterns of scoliotic curves (isolated lateral\\u000a bending curve, lateral bending combined with rotation curve). The stress on the nerve root was calculated on both sides (right\\u000a and left) of

  6. A widely displaced Galeazzi-equivalent lesion with median nerve compromise.

    PubMed

    Galanopoulos, Ilias; Fogg, Quentin; Ashwood, Neil; Fu, Katherine

    2012-01-01

    We present the case of a 14-year-old boy with a right distal radial fracture accompanied by a severely displaced complete distal ulnar physeal separation and associated median nerve compromise. This injury is known as Galeazzi-equivalent lesion in children and is an extremely rare injury associated with growth arrest. Recognition of the lesion can be difficult but wide displacement may be associated with other significant injuries such as neurovascular compromise. Prompt intervention reversed the neurological symptoms. At 10-month postoperation there was neither growth arrest nor loss of motion. Complete separation of the ulna physis remains often because of soft tissue interposition or capsule problems and prompt reduction is recommended in the literature as a priority. PMID:22907852

  7. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly.

    PubMed

    Y?lmaz, Tevfik; Turan, Yahya; Gül?en, Ismail; Dalbayrak, Sedat

    2014-04-01

    Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

  8. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly

    PubMed Central

    Y?lmaz, Tevfik; Turan, Yahya; Gül?en, ?smail; Dalbayrak, Sedat

    2014-01-01

    Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

  9. Transverse Ultrasound Assessment of Median Nerve Deformation and Displacement in the Human Carpal Tunnel during Wrist Movements

    PubMed Central

    Wang, Yuexiang; Zhao, Chunfeng; Passe, Sandra M.; Filius, Anika; Thoreson, Andrew R.; An, Kai-Nan; Amadio, Peter C.

    2013-01-01

    The symptoms of carpal tunnel syndrome, a compression neuropathy of the median nerve at the wrist, are aggravated by wrist motion, but the effect of these motions on median nerve motion are unknown. In order to better understand the biomechanics of the abnormal nerve, it is first necessary to understand normal nerve movement. The purpose of this study was to evaluate the deformation and displacement of the normal median nerve at the proximal carpal tunnel level on transverse ultrasound images during different wrist movements, in order to have a baseline for comparison with abnormal movements. Dynamic ultrasound images were obtained in both wrists of 10 asymptomatic volunteers during wrist maximal flexion, extension and ulnar deviation. In order to simplify the analysis, the initial and final shape and position of the median nerve were measured and analyzed. The circularity of the median nerve was significantly increased and the aspect ratio and perimeter were significantly decreased in the final image compared to that in the first image during wrist flexion with finger extension, wrist flexion with finger flexion and wrist ulnar deviation with finger extension (p<0.01). There were significant differences in median nerve displacement vector between finger flexion, wrist flexion with finger extension and wrist ulnar deviation with finger extension (all p<0.001). The mean amplitudes of the median nerve motion in wrist flexion with finger extension (2.36±0.79 NU), wrist flexion with finger flexion (2.46±0.84 NU) and wrist ulnar deviation with finger extension (2.86±0.51 NU) were higher than those in finger flexion (0.82±0.33 NU), wrist extension with finger extension (0.77±0.46 NU) and wrist extension with finger flexion (0.81±0.58 NU) (p<0.0001). In the normal carpal tunnel, wrist flexion and ulnar deviation could induce significant transverse displacement and deformation of the median nerve. PMID:24210862

  10. [Sciatica due to unusual causes: Tarlov cysts and nerve roots anomalies].

    PubMed

    Younes, M; Korbaa, W; Zrour, S; Bejia, I; Touzi, M; Bergaoui, N

    2009-03-01

    Tarlov cysts and nerve roots anomalies usually involve lumbosacral roots and are often asymptomatic. MRI has enabled recognition of many conditions that used to be missed by CT or myelography investigations performed for back and leg pain. However, even without additional compressive impingement (disc hernia, spondylolisthesis or lumbar canal stenosis) these anomalies can be responsible for sciatica, motor deficit and bladder sphincter dysfunction. Tarlov cysts are perinervous dilatations of the dorsal root ganglion. CT and especially MRI can reveal these cysts and their precise relations with the neighboring structures. Delayed filling of the cysts can be visualized on the myelogram. MRI is more sensitive than CT myelography for a positive diagnosis of nerve root anomalies, a differential diagnosis with disc hernia and classification of these anomalies. Surgical treatment is indicated for symptomatic Tarlov cysts and nerve root anomalies resistant to conservative treatment. Better outcome is observed in patients with an additional compressive impingement component. We report two cases of sciatica: one caused by Tarlov cysts diagnosed by MRI and the other by nerve root anomalies diagnosed by CT myelography. In both cases, conservative treatment was undertaken. The clinical, radiological and therapeutic aspects of these disorders are discussed. PMID:18809189

  11. Development of a duration threshold for modulating evoked neuronal responses after nerve root compression injury.

    PubMed

    Nicholson, Kristen J; Quindlen, Julia C; Winkelstein, Beth A

    2011-11-01

    Cervical nerve roots are susceptible to compression injuries of various durations. The duration of an applied compression has been shown to contribute to both the onset of persistent pain and also the degree of spinal cellular and molecular responses related to nociception. This study investigated the relationship between peripherally-evoked activity in spinal cord neurons during a root compression and the resulting development of axonal damage. Electrically-evoked spikes were measured in the spinal cord as a function of time during and after (post-compression) a 15 minute compression of the C7 nerve root. Compression to the root significantly (p=0.035) reduced the number of spikes that were evoked over time relative to sham. The critical time for compression to maximally reduce evoked spikes was 6.6±3.0 minutes. A second study measured the post- compression evoked neuronal activity following compression applied for a shorter, sub-threshold time (three minutes). Ten minutes after compression was removed, the discharge rate remained significantly (p=0.018) less than baseline by 58±25% relative to sham after the 15 minute compression, but returned to within 3±33% of baseline after the three minute compression. Axonal damage was evident in the nerve root at day seven after nerve root compression only after a 15 minute compression. These studies demonstrate that even a transient mechanical insult to the nerve root is sufficient to induce sustained neuronal dysfunction and axonal pathology associated with pain, and results provide support that such minor neural tissue traumas can actually induce long-lasting functional deficits. PMID:22869302

  12. Differential expression of microRNAs in dorsal root ganglia after sciatic nerve injury

    PubMed Central

    Lu, Anjie; Huang, Zufa; Zhang, Chaoyue; Zhang, Xianfang; Zhao, Jiuhong; Zhang, Haiying; Zhang, Quanpeng; Wu, Song; Yi, Xinan

    2014-01-01

    This study investigated the possible involvement of microRNAs in the regulation of genes that participate in peripheral neural regeneration. A microRNA microarray analysis was conducted and 23 microRNAs were identified whose expression was significantly changed in rat dorsal root ganglia after sciatic nerve transection. The expression of one of the downregulated microRNAs, microRNA-214, was validated using quantitative reverse transcriptase-PCR. MicroRNA-214 was predicted to target the 3?-untranslated region of Slit-Robo GTPase-activating protein 3. In situ hybridization verified that microRNA-214 was located in the cytoplasm of dorsal root ganglia primary neurons and was downregulated following sciatic nerve transection. Moreover, a combination of in situ hybridization and immunohistochemistry revealed that microRNA-214 and Slit-Robo GTPase-activating protein 3 were co-localized in dorsal root ganglion primary neurons. Western blot analysis suggested that Slit-Robo GTPase-activating protein 3 was upregulated in dorsal root ganglion neurons after sciatic nerve transection. These data demonstrate that microRNA-214 is located and differentially expressed in dorsal root ganglion primary neurons and may participate in regulating the gene expression of Slit-Robo GTPase-activating protein 3 after sciatic nerve transection. PMID:25206756

  13. Nerve repair with adipose-derived stem cells protects dorsal root ganglia neurons from apoptosis.

    PubMed

    Reid, A J; Sun, M; Wiberg, M; Downes, S; Terenghi, G; Kingham, P J

    2011-12-29

    Novel approaches are required in the clinical management of peripheral nerve injuries because current surgical techniques result in deficient sensory recovery. Microsurgery alone fails to address extensive cell death in the dorsal root ganglia (DRG), in addition to poor axonal regeneration. Incorporation of cultured cells into nerve conduits may offer a novel approach in which to combine nerve repair and enhance axonal regeneration with neuroprotective therapies. We examined apoptotic mediator expression in rat DRG neurons following repair of a 10-mm sciatic nerve gap using a novel synthetic conduit made of poly ?-caprolactone (PCL) and primed with adipose-derived stem cells (ADSC) differentiated towards a Schwann cell phenotype or with primary adult Schwann cells. Differentiated ADSC expressed a range of neurotrophic factors including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and neurotrophin-4 (NT4). Incorporation of either differentiated ADSC or Schwann cells significantly increased anti-apoptotic Bcl-2 mRNA expression (P<0.001) in the DRG, while significantly decreasing pro-apoptotic Bax (P<0.001) and caspase-3 mRNA (P<0.01) expression. Cleaved caspase-3 protein was observed in the DRG following nerve injury which was attenuated when nerve repair was performed using conduits seeded with cells. Cell incorporation into conduit repair of peripheral nerves demonstrates experimental promise as a novel intervention to prevent DRG neuronal loss. PMID:22020320

  14. Effect of acute nerve root compression on endoneurial fluid pressure and blood flow in rat dorsal root ganglia.

    PubMed

    Igarashi, Tamaki; Yabuki, Shoji; Kikuchi, Shinichi; Myers, Robert R

    2005-03-01

    The objective of the current study was to test the hypothesis that crush injury to nerve root increases endoneurial fluid pressure (EFP) and decreases blood flow in the associated dorsal root ganglion (DRG). A total of 21 adult, female Sprague-Dawley rats had their left L5 nerve root and DRG exposed. The L5 nerve root was clamped for 2 s with a vascular suture clip just proximal to the DRG (compression group). Sham-operated animals without compression were used for control (control group). EFP was recorded with a servo-null micropipette system using a glass micropipette with tip diameter of 4 mum before and after 3 h of treatment. After the final measurement of EFP, DRG was excised and processed for histology. Blood flow in the DRG was continuously monitored by laser Doppler flow meter for 3 h. Three hours after treatment, EFP was 4.7+/-2.7 cm H(2)O in the compression group and 2.2+/-1.2 cm H(2)O in the control group (P<0.05). Edema was the principal pathologic findings seen consistently in the DRG from animals in the compression group. Blood flow in the compression group was reduced 10 min after compression. This reduction was statistically significant compared with that of the control (P<0.01). An acute compression to the nerve root increased endoneurial edema, increased EFP in the associated DRG, and reduced DRG blood flow. This combination of increased EFP and decreased blood flow in the DRG may result in neuronal ischemia and sensory dysfunction. These acute pathophysiologic changes may thus have a role in the pathogenesis of low back pain and sciatica due to disc herniation and spinal canal stenosis. PMID:15734257

  15. Characterization of the turning response of dorsal root neurites toward nerve growth factor

    Microsoft Academic Search

    ROSS W. GUNDERSEN; JOHN N. BARRETT

    1980-01-01

    This study reportsthat chick dorsal root ganglion neurites undergo a rapid (20min) reorientationof theirdirection of growth in response to nerve growth factor (NGF) concentra- tion gradients in vitro.Dorsal root ganglia from chick embryos were explanted onto a Collagen- poly-L-lysine substrate. After 24-48 h in culture, NGF gradients were applied to individual growth cones via a micropipette containing 50 biological units

  16. Altered Function of Lumbar Nerve Roots in Patients With Transitional Lumbosacral Vertebrae

    Microsoft Academic Search

    Han Soo Chang; Hiroshi NAKAGAWA

    2004-01-01

    STUDY DESIGN: A retrospective study was conducted on the preoperative neurologic symptoms of patients with lumbar herniated discs. OBJECTIVE: To evaluate the possibility that the muscle innervation pattern and the sensory dermatomes of lumbar nerve roots are altered when a lumbosacral transitional vertebra is present. SUMMARY OF BACKGROUND DATA: In 1962, McCulloch et al suggested with intraoperative recordings that the

  17. Exogenous silver in dorsal root ganglia, peripheral nerve, enteric ganglia, and adrenal medulla

    Microsoft Academic Search

    J. Rungby

    1986-01-01

    Following intraperitoneal (i.p.) or oral administration of silver salts, the anatomic distribution of silver in the peripheral nervous system (PNS) has been studied. The structures examined were dorsal root ganglia, peripheral nerve (N. ischiadicus), enteric ganglia, and adrenal medulla.

  18. Morphometric Study of the Nerve Roots Around the Lateral Mass for Posterior Foraminotomy

    PubMed Central

    Hwang, Jae-Chan; Bae, Hak-Geun; Cho, Sung-Won; Cho, Sung-Jin; Park, Hyung-Ki

    2010-01-01

    Objective Morphometric data on dorsal cervical anatomy were examined in an effort to protect the nerve root near the lateral mass during posterior foraminotomy. Methods Using 25 adult formalin-fixed cadaveric cervical spines, measurements were taken at the lateral mass from C3 to C7 via a total laminectomy and a medial one-half facetectomy. The morphometric relationship between the nerve roots and structures of the lateral mass was investigated. Results from both genders were compared. Results Following the total laminectomy, from C3 to C7, the mean of the vertical distance from the medial point of the facet (MPF) of the lateral mass to the axilla of the root origin was 3.2-4.7 mm. The whole length of the exposed root had a mean of 4.2-5.8 mm. Following a medial one-half facetectomy, from C3 to C7, the mean of the vertical distance to the axilla of the root origin was 2.1-3.4 mm, based on the MPF. Mean vertical distances from the MPF to the medial point of the root that crossed the inferior margin of the intervertebral disc were 1.2-2.7 mm. The mean distance of the exposed root was 8.2-9.0 mm, and the mean angle between the dura and the nerve root was significantly different between males and females, at 53.4-68.4°. Conclusion These data will aid in reducing root injuries during posterior cervical foraminotomy. PMID:20539795

  19. The Incidence of Lumbar Discectomy after Epidural Steroid Injections or Selective Nerve Root Blocks

    PubMed Central

    Mroz, Thomas; Lieberman, Isador

    2015-01-01

    Background The purpose of this study was to determine the use of Central Epidural Steroid Injections (ESI) and Selective Nerve Root Blocks (SNRB) along with the crossover rate to lumbar discectomy in patients with a lumbar disc herniation using retrospective records database search. Butterman et al found a crossover rate for patients with symptomatic disc herniations treated with ESI of 54% (27/50), while Riew similarly found a 53% (29/55) crossover patients receiving SNRB. Methods The database was searched in a sequential Boolean style for patients with the diagnosis of a lumbar disc herniation (Displaced Lumbar Disc - 722.1) and a SNRB (64483) or ESI (62311) who subsequently underwent a Lumbar Discectomy (63030) over a three year time period from January 2004 through December 2006. Statistical analysis was preformed examining the impact of injection type, age, location, gender, and year. Results Of 482,893 patients with the diagnosis of a disc herniation, 27,799(5.76%) underwent a lumbar discectomy. The 29,941 patients who received at least one SNRB for a disc herniation, 10.80% later underwent a lumbar discectomy. The 41,420 patients who received at least one ESI for a disc herniation 9.34% later underwent a lumbar discectomy. There was a noted increase in injection procedures, particularly SNRB during the study with a greater than 50% increase. Conclusions Our examination found a much smaller, but similar crossover rate to surgery between both injection methods, which argues against one method being more effective than another in avoiding surgery. It is likely that patients are receiving these procedures more frequently during the course of conservative treatment for a disc herniation. Level of Evidence This was a Level III study. PMID:26056627

  20. Macrophage-Mediated Dorsal Root Ganglion Damage Precedes Altered Nerve Conduction in SIV-Infected Macaques

    PubMed Central

    Laast, Victoria A.; Shim, Beom; Johanek, Lisa M.; Dorsey, Jamie L.; Hauer, Peter E.; Tarwater, Patrick M.; Adams, Robert J.; Pardo, Carlos A.; McArthur, Justin C.; Ringkamp, Matthias; Mankowski, Joseph L.

    2011-01-01

    Peripheral neuropathy is the most common neurological complication of HIV-1 infection, affecting over one-third of infected individuals, including those treated with antiretroviral therapy. To study the pathogenesis of HIV-induced peripheral nervous system disease, we established a model in which SIV-infected macaques developed changes closely resembling alterations reported in components of the sensory pathway in HIV-infected individuals. Significant declines in epidermal nerve fiber density developed in SIV-infected macaques, similar to that of HIV-infected individuals with neuropathy. Changes in dorsal root ganglia (DRG) included macrophage infiltration, SIV replication in macrophages, immune activation of satellite cells, and neuronal loss. To determine whether dorsal root ganglion damage was associated with altered nerve function, we measured unmyelinated C-fiber conduction velocities (CV) in nerves of SIV-infected macaques and compared CV changes with DRG alterations. Twelve weeks postinoculation, SIV-infected macaques had significantly lower C-fiber conduction velocity in sural nerves than uninfected animals and the magnitude of conduction velocity decline correlated strongly with extent of DRG macrophage infiltration. Thus, injury to neurons in the DRG—mediated by activated macrophages—preceded altered conduction of unmyelinated nerve fibers in SIV-infected macaques, suggesting that macrophage-mediated DRG damage may be the initiating event in HIV-induced sensory neuropathy. PMID:21924225

  1. Predominant patterns of median nerve displacement and deformation during individual finger motion in early carpal tunnel syndrome.

    PubMed

    Liong, Kyrin; Lahiri, Amitabha; Lee, Shujin; Chia, Dawn; Biswas, Arijit; Lee, Heow Pueh

    2014-08-01

    Idiopathic carpal tunnel syndrome (CTS) is a common neuropathy, yet the pathologic changes do not explain the fleeting dynamic symptoms. Dynamic nerve-tendon interaction may be a contributing factor. Based on dynamic ultrasonographic examination of the carpal tunnel, we quantified nerve-tendon movement in thumb, index finger and middle finger flexion in normal subjects and those with mild-idiopathic CTS. Predominant motion patterns were identified. The nerve consistently moves volar-ulnarly. In thumb and index finger flexion, the associated tendons move similarly, whereas the tendon moves dorsoradially in middle finger flexion. Nerve displacement and deformation increased from thumb to index finger to middle finger flexion. Predomination motion patterns may be applied in computational simulations to prescribe specific motions to the tendons and to observe resultant nerve pressures. By identification of the greatest pressure-inducing motions, CTS treatment may be better developed. Symptomatic subjects displayed reduced nerve movement and deformation relative to controls, elucidating the physiologic changes that occur during mild CTS. PMID:24785444

  2. Expression and identification of olfactory receptors in sciatic nerve and dorsal root ganglia of rats.

    PubMed

    Gong, Leilei; Chen, Qianqian; Gu, Xiaosong; Li, Shiying

    2015-07-23

    The olfactory receptor (OR) genes are expressed mainly in the cell membrane of olfactory sensory neurons of the nasal epithelium, and the binding of specific odorant ligands to OR proteins leads to odor detection. ORs are also expressed in non-olfactory tissues and cells, but their functions are often elusive. In this study, microarray analysis was used to detect the presence of ORs in peripheral nerves. We found that a number of ORs were differentially expressed in sciatic nerve and dorsal root ganglia (DRGs) following sciatic nerve injury. The expression and expression profile of several ORs in sciatic nerve were verified by in situ hybridization and real time quantitative RT-PCR. We also observed that the expression of some ORs in primary culture of Schwann cells was up-regulated under H2O2 stimulation. Overall, all the results suggest that there may be a possible relationship between the differential expression of ORs in injured peripheral nerves and peripheral nerve regeneration. PMID:26071906

  3. Vasogenic edema induced by compression injury to the spinal nerve root. Distribution of intravenously injected protein tracers and gadolinium-enhanced magnetic resonance imaging.

    PubMed

    Kobayashi, S; Yoshizawa, H; Hachiya, Y; Ukai, T; Morita, T

    1993-09-01

    The function of the blood-nerve barrier appears quite unique in the nerve root. Protein tracers that were injected into the subarachnoid space passed through the nerve root sheath and entered into the capillary lumen in the endoneurial space but tracers that were injected intravenously did not appear in the endoneurial space. Marked extravasation of protein tracers in the nerve root was induced at the compressed part by strong compression (60 gram force, 30 gram force) and capillaries in the nerve root showed opening of the tight junction accompanied by an increase in vesicular transport under the electron microscope. This situation was reflected as high intensity on Gadolinium-enhanced magnetic resonance imaging. In twenty-one of fifty patients with lumbar disc herniation, the affected nerve root was strongly enhanced by Gadolinium-diethylene-triaminepentaacetic acid, indicating that the blood-nerve barrier in the affected nerve root was broken and intraradicular edema was produced in these cases. PMID:8235811

  4. The clinical significance of gadolinium enhancement of lumbar disc herniations and nerve roots on preoperative MRI

    Microsoft Academic Search

    P. C. A. J. Vroomen; S. J. M. Van Hapert; R. E. H. Van Acker; E. A. M. Beuls; A. G. H. Kessels; J. T. Wilmink

    1998-01-01

    The clinical significance of preoperative gadolinium DPTA enhancement around disc herniations and in the epidural space on\\u000a MRI is not clear. The relation of nerve root enhancement to dysfunction also remains controversial. To investigate the clinical\\u000a significance of contrast enhancement we looked at the symptoms and signs and gadolinium DPTA-enhanced images of 71 consecutive\\u000a surgical candidates in a standardised fashion.

  5. Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report

    Microsoft Academic Search

    Shinji Yoshioka; Koichi Sairyo; Toshinori Sakai; Natsuo Yasui

    2010-01-01

    We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination\\u000a of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain\\u000a and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent

  6. Increased TRPA1, TRPM8, and TRPV2 expression in dorsal root ganglia by nerve injury

    Microsoft Academic Search

    J. Frederick; M. E. Buck; D. J. Matson; D. N. Cortright

    2007-01-01

    Thermosensitive TRP channels display unique thermal responses, suggesting distinct roles mediating sensory transmission of temperature. However, whether relative expression of these channels in dorsal root ganglia (DRG) is altered in nerve injury is unknown. We developed a multiplex ribonuclease protection assay (RPA) to quantify rat TRPV1, TRPV2, TRPV3, TRPV4, TRPA1, and TRPM8 RNA levels in DRG. We used the multiplex

  7. The potential for salmon fibrin and thrombin to mitigate pain subsequent to cervical nerve root injury

    PubMed Central

    Weisshaar, Christine L.; Winer, Jessamine P.; Guarino, Benjamin B.; Janmey, Paul A.; Winkelstein, Beth A.

    2011-01-01

    Nerve root compression is a common cause of radiculopathy and induces persistent pain. Mammalian fibrin is used clinically as a coagulant but presents a variety of risks. Fish fibrin is a potential biomaterial for neural injury treatment because it promotes neurite outgrowth, is non-toxic, and clots readily at lower temperatures. This study administered salmon fibrin and thrombin following nerve root compression and measured behavioral sensitivity and glial activation in a rat pain model. Fibrin and thrombin each significantly reduced mechanical allodynia compared to injury alone (p<0.02). Painful compression with fibrin exhibited allodynia that was not different from sham for any day using stimulation by a 2 g filament; allodynia was only significantly different (p<0.043) from sham using the 4 g filament on days 1 and 3. By day 5, responses for fibrin treatment decreased to sham levels. Allodynia following compression with thrombin treatment were unchanged from sham at any time point. Macrophage infiltration at the nerve root and spinal microglial activation were only mildly modified by salmon treatments. Spinal astrocytic expression decreased significantly with fibrin (p<0.0001) but was unchanged from injury responses for thrombin treatment. Results suggest that salmon fibrin and thrombin may be suitable biomaterials to mitigate pain. PMID:21944723

  8. [Juxta-facet Cyst Associated with Conjoined Nerve Roots:A Case Report].

    PubMed

    Matsumoto, Naoki; Sasaki, Nobuhiro; Fukuda, Miyuki; Ueda, Shigeo; Hoshimaru, Minoru

    2015-06-01

    We report a case of a patient with a juxta-facet cyst and conjoined nerve roots. A 66-year-old man presented with left leg pain from the past 4 months. Neurological examinations revealed L5 and S1 radiculopathy on the left side. Magnetic resonance imaging(MRI)detected a mass lesion located near the left intervertebral joint at the level of L5/S1 and canal stenosis at the level of L3/L4. A juxta-facet cyst was diagnosed by arthrography. We performed a curettage and resection of the mass, posterior lumbar interbody fusion at the level of L5/S1, and laminectomy at the level of L3/L4. Conjoined left L5/S1 nerve roots were observed during surgery. The patient recovered from the symptoms of L5 and S1 radiculopathy immediately after surgery. Postoperative review of the preoperative computed tomography images revealed bony abnormality in the L5/S1 joint. We speculate that the bony abnormality may be associated with the development of conjoined nerve roots and the juxta-facet cyst. PMID:26015382

  9. Severe acute inflammatory demyelinating polyradiculoneuropathy with persistent weakness associated with tumor-like nerve root enlargement.

    PubMed

    Stoll, Sharon S; Rakocevic, Goran

    2015-06-01

    We report a 23-year-old woman with rapid onset of proximal and distal limb weakness and areflexia, associated with tumor-like spinal nerve root enlargement and markedly elevated cerebrospinal fluid protein. Our patient developed the inability to walk within days, without preceding illness. Within two weeks, she had near-complete bilateral wrist and foot drop. Her cranial nerves and respiratory function remained intact. She received intravenous immunoglobulin early on for suspected Guillain-barre syndrome but remained wheelchair-bound until 6 Plasma exchange sessions were completed. After that, she continued to improve with intravenous immunoglobulin dosed every 3-4 weeks. Prominent demyelinating features were found on NCS, with cerebrospinal fluid protein of 415 mg/dL. Comprehensive infectious work-up was negative. Magnetic resonance imaging of lumbosacral and cervical spine showed tumor-like masses mistaken for neurofibromatosis (axial diameter, 7.5-10 mm). Repeated magnetic resonance imaging 6 months later showed persistent nerve root enlargement, despite the patient's improved functional status. PMID:25996968

  10. Microvascular decompression of trigeminal nerve root for treatment of a patient with hemimasticatory spasm.

    PubMed

    Dou, Ning-Ning; Zhong, Jun; Zhou, Qiu-Meng; Zhu, Jin; Wang, Yong-Nan; Li, Shi-Ting

    2014-05-01

    Hemimasticatory spasm is a rare disease; with little knowledge of the pathogenesis, it has still been intractable today. We presented a 56-year-old woman with involuntary painful spasm in her left masseter muscle for 11 years. The patient was successfully treated with microvascular decompression surgery. An offending superior cerebellar artery was found to contact with the motor branch of the trigeminal nerve root, which was then removed away and pieces of soft wadding were interposed between the nerve and the vessel to assure the separation. Postoperatively, the symptom totally disappeared and no recurrence was observed during the 7 months' follow-up. The treatment as well as the pathogenesis of the disease was reviewed, and we put forward a new hypothesis. PMID:24657975

  11. Nerve loop around the axillary vessels by the roots of the median nerve a rare variation in a south Indian male cadaver: a case report

    PubMed Central

    2009-01-01

    Introduction Median nerve is normally formed by the union of medial and lateral root arising from the medial and the lateral cords of the brachial plexus respectively. However, variations in the formation and its relation with the axillary vessels are not uncommon. Therefore, knowledge of the variations in the nerve formation and course is useful for the clinicians during surgery and for differential diagnosis of uncommon clinical conditions. Case presentation During the routine dissection in the department of anatomy, Kasturba Medical Collage, Manipal, India, we found unique anatomical variations in the formation and the course of the roots of the median nerve forming the neural loops around the axillary artery and vein. Conclusion Here we report the detailed description of these variations along with its clinical, embryological relevance and review of literature. PMID:19946489

  12. [Lumbar nerve root pain with fever in tropical area: posterior spinal tuberculosis].

    PubMed

    Ouédraogo, D D; Daboiko, J C; Eti, E; Ouali, B; Ouattara, B; Gbané, M; Gbazi, C; Kouakou, N M

    2008-12-01

    The purpose of this report is to describe the case of tuberculosis osteitis of the posterior vertebral arch in a 35-year-old man with recent history of pulmonary tuberculosis. Clinical findings were pain due to bilateral inflammation of the lumbar nerve roots, fistulised cold abcess and motor deficit in both lower extremities. The tomodensitometry demonstrated a lytic bone lesion involving the spinous process of the second lumbar vertebra in association with spondylitis and a large paravertebral abscess with calcification typical of tuberculosis. Cure was achieved by a single 12-month course of appropriate treatment. PMID:19639843

  13. Nerve root infiltration of the first sacral root with MRI guidance

    Microsoft Academic Search

    Risto Ojala; Erkki Vahala; Jaro Karppinen; Rauli Klemola; Roberto Blanco-Sequeiros; Teuvo Vaara; Osmo Tervonen

    2000-01-01

    The purpose of this clinical trial was to describe the meth- odology and evaluate the accuracy of optical tracking- based magnetic resonance (MR)-guided infiltration of the first sacral (S1) root. Thirty-five infiltrations were per- formed on 34 patients with a 0.23-T open C-arm magnet installed in a fully equipped operation room with large- screen (36 inches) display and optical navigator

  14. Increased TRPA1, TRPM8, and TRPV2 expression in dorsal root ganglia by nerve injury.

    PubMed

    Frederick, J; Buck, M E; Matson, D J; Cortright, D N

    2007-07-13

    Thermosensitive TRP channels display unique thermal responses, suggesting distinct roles mediating sensory transmission of temperature. However, whether relative expression of these channels in dorsal root ganglia (DRG) is altered in nerve injury is unknown. We developed a multiplex ribonuclease protection assay (RPA) to quantify rat TRPV1, TRPV2, TRPV3, TRPV4, TRPA1, and TRPM8 RNA levels in DRG. We used the multiplex RPA to measure thermosensitive TRP channel RNA levels in DRG from RTX-treated rats (300 microg/kg) or rats with unilateral sciatic nerve chronic constriction injury (CCI). TRPV1 and TRPA1 RNA were significantly decreased in DRG from RTX-treated rats, indicating functional colocalization of TRPA1 and TRPV1 in sensory nociceptors. In DRG from CCI rats, TRPA1, TRPV2, and TRPM8 RNA showed slight but significant increases ipsilateral to peripheral nerve injury. Our findings support the hypothesis that increased TRP channel expression in sensory neurons may contribute to mechanical and cold hypersensitivity. PMID:17517374

  15. Increased autophagic activity in dorsal root ganglion attenuates neuropathic pain following peripheral nerve injury.

    PubMed

    Guo, Jian-Shuang; Jing, Peng-Bo; Wang, Ji-An; Zhang, Rui; Jiang, Bao-Chun; Gao, Yong-Jing; Zhang, Zhi-Jun

    2015-07-10

    Autophagy is a process of cellular self-cannibalization, and provides an adaptive mechanism to protect cells against diverse pathological settings. Following peripheral nerve injury, autophagic process was changed in Schwann cells and spinal neurons and glial cells, implicating a vital role of autophagy in chronic pain. However, little is known about the role of autophagy in dorsal root ganglion (DRG) in neuropathic pain. In the present study, we investigated the autophagic process in DRG and its effect on neuropathic pain induced by L5 spinal nerve ligation (SNL). The level of microtubule associated protein 1 light chain 3 (LC3)-II, a general marker for autophagy, was increased in L5 DRG after SNL. Immunofluorescence staining showed that LC3-II puncta were observed in DRG neurons after SNL. Injection of autophagy inducer rapamycin into L5 DRG before or after SNL dose-dependently attenuated neuropathic pain. The expression of LC3 was enhanced in L5 DRG by rapamycin. These data suggest that the autophagy in L5 DRG neurons is a defensive reaction to L5 spinal nerve injury, and pharmacological enhancement of autophagy may be a potential treatment to prevent the onset and chronification of neuropathic pain. PMID:26021876

  16. 2028 OPTICS LETTERS / Vol. 29, No. 17 / September 1, 2004 Noncontact measurement of nerve displacement

    E-print Network

    Seung, Sebastian

    .3180, 170.3880. Nerve fibers exhibit rapid outward lateral surface dis- placements during the action. Laser Doppler vibrometry,5 speckle vi- brometry,6 and laser feedback interferometry7 are sensitive incorporates both fiber and free-space elements (Fig. 1). Light from a fiber- coupled superluminescent diode

  17. Morphometric Investigations of the Connections between the Posterior C-1 Root and the Accessory Nerve in the Human Cranial Cervical Region

    Microsoft Academic Search

    U. Schneider; A. Biörnsen; R. Hagenah

    1996-01-01

    The anastomosis of the spinal section of the accessory nerve and the posterior C-1 root was examined in eight human corpses at the light-microscopical level by image analysis. The numbers of nerve fibers caudal and cranial to the anastomosis were compared. The morphometric data suggest that somatic efferent fibers of the spinal accessory nerve extend to proprioceptors in the sternocleidomastoideus

  18. C5 Nerve root palsies following cervical spine surgery: A review

    PubMed Central

    Epstein, Nancy E.; Hollingsworth, Renee

    2015-01-01

    Background: Cervical C5 nerve root palsies may occur in between 0% and 30% of routine anterior or posterior cervical spine operations. They are largely attributed to traction injuries/increased cord migration following anterior/posterior decompressions. Of interest, almost all studies cite spontaneous resolution of these deficits without surgery with 3–24 postoperative months. Methods: Different studies cite various frequencies for C5 root palsies following anterior or posterior cervical spine surgery. In their combined anterior/posterior series involving C4-C5 level decompressions, Libelski et al. cited up to a 12% incidence of C5 palsies. In Gu et al. series, C5 root palsies occurred in 3.1% of double-door laminoplasty, 4.5% of open-door laminoplasty, and 11.3% of laminectomy. Miller et al. observed an intermediate 6.9% frequency of C5 palsies followed by posterior cervical decompressions and fusions (PCDF). Results: Gu et al. also identified multiple risk factors for developing C5 palsies following posterior surgery; male gender, ossification of the posterior longitudinal ligament (OPLL), narrower foramina, laminectomy, and marked dorsal spinal cord drift. Miller et al. also identified an average $1918 increased cost for physical/occupational therapy for patients with C5 palsies. Conclusions: The incidence of C5 root deficits for anterior/posterior cervical surgery at C4-C5 was 12% in one series, and ranged up to 11.3% for laminectomies, while others cited 0–30%. Although identification of preoperative risk factors for C5 root deficits may help educate patients regarding these risks, there is no clear method for their avoidance at this time. PMID:26005577

  19. Slowed motor conduction in lumbosacral nerve roots in cauda equina lesions: a new diagnostic technique.

    PubMed Central

    Swash, M; Snooks, S J

    1986-01-01

    New techniques have been developed for the electrophysiological assessment of patients with suspected cauda equina lesions using transcutaneous spinal stimulation (500-1500 V: time constant 50 microseconds) to measure motor latencies to the external and sphincter and puborectalis muscles from L1 and L4 vertebral levels. These latencies represent motor conduction in the S3 and S4 motor roots of the cauda equina between these levels. Similarly motor latencies can be recorded from spinal stimulation to the anterior tibial muscles (L4 and L5 motor roots). Transrectal stimulation of the pudendal nerves is used to measure the pudendal nerve terminal motor latency. In 32 control subjects, matched for age and sex, mean motor latencies from L1 and L4 spinal stimulation were 5.5 +/- 0.4 ms and 4.4 +/- 0.4 ms (mean + SD). In the 10 patients with cauda equina disease including ependymoma, spinal stenosis, arachnoiditis and trauma, these latencies were 7.2 +/- 0.8 ms and 4.6 +/- 0.9 ms, a significant increase in the L1 latency. The L1/L4 latency ratios to the puborectalis muscle were 1.36 +/- 0.09 in control subjects and 1.72 +/- 0.13 in cauda equina patients. Pudendal nerve terminal motor latencies were normal in eight of the 10 patients with cauda equina disease. The single fibre EMG fibre density in the external and sphincter muscle (normal, 1.5 +/- 0.16) was increased in patients with cauda equina lesions (1.73 +/- 0.28), but was increased more than two standard deviations from the mean only in three patients. This increase in fibre density was not of diagnostic value since it was also found in two of the four patients with low back pain. Slowing of motor conduction in the cauda equina is thus a useful indication of damage to these intraspinal motor roots. These investigations can be used in the selection of patients for myelography, and to follow progress in patients managed conservatively. Images PMID:3018168

  20. Meralgia paresthetica-like syndrome may be caused by transient lumbar nerve root injury without definite compression: a case report.

    PubMed

    Dharmasaroja, Pornpatr; Dharmasaroja, Permphan

    2010-12-01

    Meralgia paresthetica is a well-known sensory syndrome describing paresthesia and/or anesthesia in the anterolateral aspect of the thigh that is supplied by the lateral femoral cutaneous nerve. Compression of the nerve usually occurs at the point where it passes between the anterior superior iliac spine and the inguinal ligament. Proximal lesions such as lumbar radiculopathy, lumbar disc herniation, and spinal stenosis have been reported to cause meralgia paresthetica-like syndrome. These proximal lesions directly injure L2 and L3 spinal nerve roots and cause a constant compression of the nerve roots. The presented paper introduces a hypothesis that this syndrome can be caused by transient injury to the L2 and L3 nerve roots by the upper adjacent disc bulge without definite compression. This hypothesis is supported by lumbar spine magnetic resonance imaging of a patient presenting with a meralgia paresthetica-like symptom during bending forward and twisting of the body, showing no L2/L3 herniated disc but mildly posterior bulging of T12/L1 disc. This hypothesis emphasizes an importance of appropriate postures in patients with meralgia paresthetica-like symptoms in order to prevent long-term morbidity. PMID:21294431

  1. Movements elicited by electrical stimulation of muscles, nerves, intermediate spinal cord, and spinal roots in anesthetized and decerebrate cats

    Microsoft Academic Search

    Yoichiro Aoyagi; Vivian K. Mushahwar; Richard B. Stein; Arthur Prochazka

    2004-01-01

    Electrical stimulation offers the possibility of restoring motor function of paralyzed limbs after spinal-cord injury or stroke, but few data are available to compare possible sites of stimulation, such as muscle, nerve, spinal roots, or spinal cord. The aim of this study was to establish some characteristics of stimulation at these sites in the anesthetized and midcollicular decerebrate cat. The

  2. Root canal

    MedlinePLUS

    A root canal is a dental procedure to remove dead or dying nerve tissue and bacteria from inside a tooth. ... A root canal is done if you have an infection that affects the nerve in the root of a tooth. ...

  3. Spinal somatosensory evoked potential evaluation of acute nerve-root injury associated with pedicle-screw placement procedures: an experimental study.

    PubMed

    Jou, I-Ming; Hsu, Che-Chia; Chern, Tai-Chang; Chen, Wen-Yi; Dau, Yuan-Chang

    2003-03-01

    Pedicle screws for spinal fixation risk neural damage because of the proximity between screw and nerve root. We assessed whether spinal somatosensory evoked potential (SSEP) could selectively detect pedicle-screw-related acute isolated nerve injury. Because pedicle screws are too large for a rat's spine, we inserted a K-wire close to the pedicle in 32 rats, intending not to injure the nerve root in eight (controls), and to injure the L4 or L5 root in 24. We used sciatic-nerve-elicited SSEP pre- and postinsertion. Radiologic, histologic, and postmortem observations confirmed the level and degree of root injury. Sciatic (SFI), tibial (TFI), and peroneal function indices (PFI) were calculated and correlated with changes in potential. Although not specific for injuries to different roots, amplitude reduction immediately postinsertion was significant in the experimental groups. Animals with the offending wire left in place for one hour showed a further non-significant deterioration of amplitude. Electrophysiologic changes correlated with SFI and histologic findings in all groups. SSEP monitoring provided reliable, useful diagnostic and intraoperative information about the functional integrity of single nerve-root injury. These findings are clinically relevant to acute nerve-root injury and pedicle-screw insertion. If a nerve-root irritant remains in place, a considerable neurologic deficit will occur. PMID:12568971

  4. The effect of tendon excursion velocity on longitudinal median nerve displacement: differences between carpal tunnel syndrome patients and controls.

    PubMed

    Filius, Anika; Thoreson, Andrew R; Wang, Yuexiang; Passe, Sandra M; Zhao, Chunfeng; An, Kai-Nan; Amadio, Peter C

    2015-04-01

    The subsynovial connective tissue (SSCT) is a viscoelastic structure connecting the median nerve (MN) and the flexor tendons in the carpal tunnel. Increased strain rates increases stiffness in viscoelastic tissues, and thereby its capacity to transfer shear load. Therefore, tendon excursion velocity may impact the MN displacement. In carpal tunnel syndrome (CTS) the SSCT is fibrotic and may be ruptured, and this may affect MN motion. In this study, ultrasonography was performed on 14 wrists of healthy controls and 25 wrists of CTS patients during controlled finger motions performed at three different velocities. Longitudinal MN and tendon excursion were assessed using a custom speckle tracking algorithm and compared across the three different velocities. CTS patients exhibited significantly less MN motion than controls (p???0.002). While in general, MN displacement increased with increasing tendon excursion velocity (p???0.031). These findings are consistent with current knowledge of SSCT mechanics in CTS, in which in some patients the fibrotic SSCT appears to have ruptured from the tendon surface. PMID:25640903

  5. Displacement of the contents of dentinal tubules and sensory transduction in intradental nerves of the cat.

    PubMed

    Andrew, D; Matthews, B

    2000-12-15

    Experiments were performed on anaesthetized cats to test the hypothesis that fluid flow through dentinal tubules is part of the mechanism involved in the transduction of pain-producing stimuli in teeth. In 11 animals, fluid flow through dentine and single- and multi-unit activity in intradental nerves were recorded simultaneously during the application of changes in hydrostatic pressure (-500 to +500 mm Hg) to exposed dentine. Seventeen A-fibres (conduction velocity (CV), 10.6-55.1 m s(-1)) were isolated that were pressure sensitive. The thresholds of these units in terms of dentinal fluid flow were in the range 0.3-2.1 nl s(-1) mm(-2) during outward flow from the pulp and 2.0-3.5 nl s(-1) mm(-2) during inward flow. All the units were more sensitive to outward than inward flow. Twenty-eight units (CV, 0.6-48.8 m s-1) were not pressure sensitive, and 12 of these had conduction velocities in the C-fibre range (< 2.5 m s(-1)). The velocities of the tubular contents were calculated by estimating the number and diameters of dentinal tubules exposed. At the threshold of single-fibre responses these velocities were in the range 31.7-222.9 microm s(-1) during outward flow 211.4-369.6 microm s-1 during inward flow. Repetitive pressure stimulation of dentine resulted in a progressive reduction in the evoked discharge, which was probably due to pulp damage. In seven animals, 10 single intradental nerve fibres were selected that responded to hydrostatic pressure stimuli and their responses to the application of hot, cold, osmotic, mechanical and drying stimuli to exposed dentine were investigated. With these stimuli dentinal fluid flow could not be recorded in vivo for technical reasons and was therefore recorded in vitro after completion of the electrophysiological recordings. With each form of stimulus, the discharge evoked in vivo was closely related to the flow predicted from the in vitro measurements. The results were therefore consistent with the hypothesis that the stimuli act through a common transduction mechanism that involves fluid flow through dentine. PMID:11118506

  6. Charcot-Marie-Tooth syndrome and neurofibromatosis type 1 with multiple neurofibromas of the entire spinal nerve roots

    PubMed Central

    Onu, David O; Hunn, Andrew W; Peters-Willke, Jens

    2013-01-01

    The coexistence of polyneuropathy which has the definite clinical and electromyographical findings consistent with Charcot-Marie-Tooth (CMT) syndrome and neurofibromatosis type 1 (NF1) has infrequently been reported. We describe a patient with both CMT and NF1, who had multiple neurofibromas involving the entire spinal neural axis. In addition, he had multiple neurofibromas distributed within the ileopsoas and gluteus muscles and subcutaneous tissues. These lesions were detected readily by MRI and the patient underwent successful surgical resection of the largest tumours compressing bilateral C2 nerve roots. To our knowledge, this is the first reported case of CMT syndrome coexisting with NF1 in which multiple neurofibromas involved the entire spinal nerve roots. We discuss the diagnostic and therapeutic challenges, emphasising the role of MRI and electrophysiology in such cases and provide a literature review. PMID:23853192

  7. Paresis of the L5 nerve root after reduction of low-grade lumbosacral dysplastic spondylolisthesis: a case report.

    PubMed

    Lykissas, Marios G; Aichmair, Alexander; Widmann, Roger; Sama, Andrew A

    2014-09-01

    We present a unique case of a 16-year-old patient who underwent lumbar decompression surgery (L4-S1), low-grade spondylolisthesis reduction surgery at L5-S1, and posterior instrumented fusion from L4 to the pelvis. Neurologic monitoring did not show any sustained changes throughout the operation. The patient was awoken from endotracheal anesthesia with grade 0 muscle function of the left extensor hallucis longus and tibialis anterior muscles resulting in left-sided foot drop. At the last follow-up 12 months after surgery, the patient had partial recovery, with grade 4 muscle function of the left extensor hallucis longus and tibialis anterior muscles. We suggest that early identification with direct nerve root stimulation and wake-up test immediately after reduction of spondylolisthesis will allow prompt release of the reduction and further foramen exploration, and increase the possibility of good postoperative nerve root recovery. PMID:24887052

  8. The comparative performance of Roots type aircraft engine superchargers as affected by change in impeller speed and displacement

    NASA Technical Reports Server (NTRS)

    Ware, Marsden; Wilson, Ernest E

    1929-01-01

    This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements. According to simple theory, when assuming no losses, the air weight handled and the power required for a given pressure difference are directly proportional to the speed and the displacement. These simple relations are altered considerably by the losses. When comparing the performance of different sizes of machines whose impeller speeds are so related that the same service requirements are met, it is found that the individual effects of speed and displacement are canceled to a large extent, and the only considerable difference is the difference in the power losses which decrease with increase in the displacement and the accompanying decrease in speed. This difference is small in relation to the net power of the engine supercharger unit, so that a supercharger with short impellers may be used in those applications where the space available is very limited with any considerable sacrifice in performance.

  9. Neuromuscular nicotinic receptors mediate bladder contractions following bladder reinnervation with somatic to autonomic nerve transfer after decentralization by spinal root transection

    PubMed Central

    Gomez-Amaya, Sandra M.; Barbe, Mary F.; Lamarre, Neil S.; Brown, Justin M.; Braverman, Alan S.; Ruggieri, Michael R.

    2015-01-01

    This study investigates whether the reinnervated neuronal pathway mediates contraction via the same neurotransmitter and receptor mechanisms as the original pathway. Following bladder decentralization by transection of sacral roots, peripheral nerve transfer was performed with bilateral genitofemoral to pelvic nerve transfer (GFNT) and unilateral (left) femoral nerve to bilateral pelvic nerve transfer (FNT). Reinnervation was assessed 7.5 months post operatively by monitoring bladder pressure during electrical stimulation of the transferred nerves, spinal ventral roots, and spinal cord. Of the 17 animals with GFNT, 14 (82%) demonstrated functional bladder reinnervation as evidenced by increased bladder pressure during stimulation of the transferred GFN or the L3 or L4 spinal ventral roots. Lumbar spinal cord stimulation caused increased bladder pressure in 9 of 10 (90%) animals with FNT. Succinylcholine (SCh) virtually eliminated bladder pressure increases induced by electrical stimulation of the transferred somatic nerves or the lumbar spinal segments that contribute axons to these donor nerves. In control animals (either un-operated or sham-operated) SCh had no effect on nerve evoked bladder pressure increases but substantially reduced urethra and anal sphincter pressure induced by stimulation of either the lumbosacral spinal cord or the S2-3 spinal ventral roots. The reinnervated detrusor muscles of GFNT and FNT animals also contained increased alpha1 nicotinic receptor subunit immunoreactivity in punctate dots on detrusor muscle fascicles and in neuronal cell bodies, staining not observed in control animals. PMID:25444958

  10. The topography of root fibres within the sciatic nerve trunk of the dog.

    PubMed Central

    Ueyama, T

    1978-01-01

    The architecture of the fibres in the sciatic nerve of the dog has been analysed by following the degeneration of fibres resulting from division of the individual spinal nerves which contribute to the sciatic nerve. A pattern has been demonstrated which varies in part with the size of the contribution to the sciatic nerve from each of the spinal nerves L6, L7 and S1. The redistribution of the fibres of each spinal nerve to form the various branches of the sciatic nerve is also described, and the significance of these arrangements is discussed. Images Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 PMID:721690

  11. Root negative gravitropism is accompanied with displacing of columella amyloplasts to the statocyte upper longitudinal cell wall

    NASA Astrophysics Data System (ADS)

    Kordyum, Elizabeth; Sobol, Margaryta; Kalinina, Yana; Bogatina, Nina; Kondrachuk, Alexander

    Recently it was shown that roots reveal negative gravitropism in the weak combined magnetic field (CMF) with the frequency resonance to the cyclotron frequency of Ca2+ ions. A negative gravitropic reaction in the CMF occurs by a usual physiological process. Experiments in the CMF confirmed that gravitropism is plastid-based and Ca2+ ions participate in this process. Unlike control, amyloplasts-statoliths are not displacing on the lower side of a gravistimulated root but tend to group in the center of a statocyte during 30 min under gravistimulation in the CMF. In an hour of gravistimulation, they are localized near one of the statocyte longitudinal wall. Now we determined that amyloplasts are localized along the statocyte upper longitudinal side. It is of a special interest that a root is bending to the same direction with displacing of amyloplasts: in positive gravitropism - downwards, in negative gravitropism - upwards. On the basis of the obtained data there is a question, what forces promote displacing of amyloplasts against a gravitational vector? In the paper, three possible explanations are discussed: 1) CMF + Ca2+ action on the distribution of elastic forces in cytoskeleton, 2) CMF + Ca2+ action on the distribution of electric field in statocytes, and 3) CMF action on energy and direction of Ca2+ ion rotation according to the ion cyclotron resonance model that can lead to paradoxical Ca2+ redistribution.

  12. Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: A prospective comparison study between total and hemicontralateral C7 nerve root transfer

    PubMed Central

    Tu, Yuan-Kun; Tsai, Yi-Jung; Chang, Chih-Han; Su, Fong-Chin; Hsiao, Chih-Kun; Tan, Jacqueline Siau-Woon

    2014-01-01

    Purpose: We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi-CC7 transfer, on total root avulsion brachial plexus injuries (BPI). Methods: Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi-CC7 transfer for hand function, while group 2 (n = 20) received total-CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow-up. Results: Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves. Conclusions: Total-CC7 transfer had better hand recovery but more donor complications than hemi-CC7. Neurotization on both supra-scapular and axillary nerves improved shoulder recovery. © 2013 The Authors. Microsurgery published by Wiley Periodicals, Inc. Microsurgery 34:91–101, 2014. PMID:23913440

  13. Blood-nerve barrier: distribution of anionic sites on the endothelial plasma membrane and basal lamina of dorsal root ganglia.

    PubMed

    Bush, M S; Reid, A R; Allt, G

    1991-09-01

    Previous investigations of the blood-nerve barrier have correlated the greater permeability of ganglionic endoneurial vessels, compared to those of nerve trunks, with the presence of fenestrations and open intercellular junctions. Recent studies have demonstrated reduced endothelial cell surface charge in blood vessels showing greater permeability. To determine the distribution of anionic sites on the plasma membranes and basal laminae of endothelial cells in dorsal root ganglia, cationic colloidal gold and cationic ferritin were used. Electron microscopy revealed the existence of endothelial microdomains with differing labelling densities. Labelling indicated that caveolar and fenestral diaphragms and basal laminae are highly anionic at physiological pH, luminal plasma membranes and endothelial processes are moderately charged and abluminal plasma membranes are weakly anionic. Tracers did not occur in caveolae or cytoplasmic vesicles. In vitro tracer experiments at pH values of 7.3, 5.0, 3.5 and 2.0 indicated that the anionic charge on the various endothelial domains was contributed by chemical groups with differing pKa values. In summary, the labelling of ganglionic and sciatic nerve vessels was similar except for the heavy labelling of diaphragms in a minority of endoneurial vessels in ganglia. This difference is likely to account in part for the greater permeability of ganglionic endoneurial vessels. The results are discussed with regard to the blood-nerve and -brain barriers and vascular permeability in other tissues and a comparison made between the ultrastructure and anionic microdomains of epi-, peri- and endoneurial vessels of dorsal root ganglia and sciatic nerves. PMID:1960538

  14. Long non-coding RNA uc.217 regulates neurite outgrowth in dorsal root ganglion neurons following peripheral nerve injury.

    PubMed

    Yao, Chun; Wang, Jing; Zhang, Honghong; Zhou, Songlin; Qian, Tianmei; Ding, Fei; Gu, Xiaosong; Yu, Bin

    2015-07-01

    The intrinsic regeneration capacity of dorsal root ganglion (DRG) neurons can be activated after sciatic nerve injury, and peripheral nerve regeneration is a complex process regulated by multiple molecular responses and signaling pathways. Long non-coding RNAs (lncRNAs) are RNA transcripts > 200 nucleotides in length without protein-coding potential. They regulate gene expression at epigenetic, transcriptional and post-transcriptional levels, and are thus involved in many biological processes and human diseases. However, the role and mechanisms of lncRNAs in regulating the responses of DRG neurons to sciatic nerve injury are not fully investigated. We have previously analysed the expression profiles of lncRNAs and mRNAs in L4-6 DRGs, following rat sciatic nerve transection, by microarray analysis, and constructed a coexpression network of dysregulated lncRNAs and coding genes. In this study, one of these dysregulated lncRNAs, uc.217, was chosen for detailed examination of its expression changes and regulative functions in regenerative DRG neuronal outgrowth. Quantitative real-time PCR and in situ hybridisation confirmed that the expression of uc.217 was down-regulated in DRG neurons after sciatic nerve injury. Silencing of uc.217 expression by small interfering RNA could significantly promote neurite outgrowth in cultured DRG neurons. Moreover, bioinformatic analysis and experimental validation were performed to identify several potential targets of uc.217, which were involved in the regulation of DRG neuron outgrowth. Collectively, our results suggested that a new lncRNA, uc.217, played an important regulative role in peripheral nerve regeneration. PMID:26032672

  15. Heterogeneous responses of dorsal root ganglion neurons in neuropathies induced by peripheral nerve trauma and the antiretroviral drug stavudine

    PubMed Central

    Boateng, EK; Novejarque, A; Pheby, T; Rice, ASC; Huang, W

    2015-01-01

    Background Heterogeneity is increasingly recognized in clinical presentation of neuropathic pain (NP), but less often recognized in animal models. Neurochemical dysregulation in rodent dorsal root ganglia (DRG) is associated with peripheral nerve trauma, but poorly studied in non-traumatic NP conditions. Methods This study aimed to investigate the temporal expressions of activating transcription factor-3 (ATF-3), growth-associated protein-43 (GAP-43), neuropeptide Y (NPY) and galanin in traumatic and non-traumatic rat models of neuropathies associated with NP. Expressions of these markers were examined in the DRG at different time points following tibial nerve transection (TNT) injury and antiretroviral drug stavudine (d4T) administration using immunohistochemistry. The development of sensory gain following these insults was assessed by measuring limb withdrawal to a punctate mechanical stimulus. Results Both TNT-injured and d4T-treated rats developed hindpaw mechanical hypersensitivity. Robust expressions of ATF-3, GAP-43, NPY and galanin in both small- and large-sized L5 DRG neurons were observed in the DRG from TNT-injured rats. In contrast, d4T-treated rats did not exhibit any significant neurochemical changes in the DRG. Conclusions Taken together, the results suggest that ATF-3, GAP-43, NPY and galanin are likely indicators of nerve trauma-associated processes and not generic markers for NP. These experiments also demonstrate distinct expression patterns of neurochemical markers in the DRG and emphasize the mechanistic difference between nerve trauma and antiretroviral drug-associated NP. PMID:25070481

  16. Differential distribution of thyroid hormone receptor isoform in rat dorsal root ganglia and sciatic nerve in vivo and in vitro.

    PubMed

    Glauser, L; Barakat Walter, I

    1997-03-01

    Using autoradiographic techniques carried out under precise conditions we previously demonstrated that both sensory neurons and peripheral glial cells in dorsal root ganglia (DRG) or sciatic nerve, possess specific [125I]-labeled T3 binding sites. Thyroid hormone receptors (TR) include several isoforms (TR alpha(1), TR alpha(2), TR beta(1), TR beta(2...)) The present study demonstrates that while sensory neurons and peripheral glial cells both possess functional TR, they express a differential expression of TR isoforms. Using a panel of antisera to specific for the TR alpha-common (alpha(1) and alpha(2)), TR alpha-1 or TR beta-1 isoforms, we detected TRs isoform localization at the cellular level during DRG and sciatic nerve development and regeneration. Immunohistochemical analysis revealed that during embryonic life, sensory neurons express TR alpha-common and TR beta-1 rather than TR alpha-1. The number of TR alpha-common and TR beta-1 positive neurons as well as the intensity of labeling increased during the first two postnatal weeks and remained more or less stable in adult life. TR alpha-1 immunoreactivity, which was undetectable in embryonic sensory neurons, became discreetly visible in neurons after birth. In developing DRG and sciatic nerves, Schwann cells exhibited TR alpha-common and TR alpha-1 rather than TR beta-1 immunolabeling. The appearance of TR alpha-common and alpha-1 isoform immunoreactivity in the sciatic nerve was restricted to a short period ranging from E17 up to two postnatal weeks. By comparing TR alpha-common and TR alpha-1 immunostaining we can deduce that Schwann cells primarily express TR alpha-1. Afterwards, in adult rat sciatic nerve TR alpha isoforms was no more detected. However transection of sciatic nerve caused a reexpression of TR alpha isoforms in degenerating nerve. The prevalence of TR alpha in Schwann cells in vivo was correlated with in vitro results. The differential expression of TR alpha and beta by sensory neurons and Schwann cells indicates that the feedback regulation of circulating thyroid hormone could occur by binding to either the alpha or beta TR isoforms. Moreover, the presence of multiple receptor isoforms in developing sensory neurons suggests that thyroid hormone uses multiple signaling pathways to regulate DRG and sciatic nerve development. PMID:9089473

  17. Thyroid hormone reduces the loss of axotomized sensory neurons in dorsal root ganglia after sciatic nerve transection in adult rat.

    PubMed

    Schenker, Michel; Kraftsik, Rudolf; Glauser, Liliane; Kuntzer, Thierry; Bogousslavsky, Julien; Barakat-Walter, Ibtissam

    2003-11-01

    We have shown that a local administration of thyroid hormones (T3) at the level of transected rat sciatic nerve induced a significant increase in the number of regenerated axons. To address the question of whether local administration of T3 rescues the axotomized sensory neurons from death, in the present study we estimated the total number of surviving neurons per dorsal root ganglion (DRG) in three experimental group animals. Forty-five days following rat sciatic nerve transection, the lumbar (L4 and L5) DRG were removed from PBS-control, T3-treated as well as from unoperated rats, and serial sections (1 microm) were cut. The physical dissector method was used to estimate the total number of sensory neurons in the DRGs. Our results revealed that in PBS-control rats transection of sciatic nerve leads to a significant (P < 0.001) decrease in the mean number of sensory neurons (8743.8 +/- 748.6) compared with the number of neurons in nontransected ganglion (mean 13,293.7 +/- 1368.4). However, administration of T3 immediately after sciatic nerve transection rescues a great number of axotomized neurons so that their mean neuron number (12,045.8 +/- 929.8) is not significantly different from the mean number of neurons in the nontransected ganglion. In addition, the volume of ganglia showed a similar tendency. These results suggest that T3 rescues a high number of axotomized sensory neurons from death and allows these cells to grow new axons. We believe that the relative preservation of neurons is important in considering future therapeutic approaches of human peripheral nerve lesion and sensory neuropathy. PMID:14637094

  18. The Response of Dorsal Root Ganglion Axons to Nerve Growth Factor Gradients Depends on Spinal Level

    E-print Network

    Goodhill, Geoffrey J.

    of NGF increases nerve regeneration and prevents axotomy-induced neuronal changes, highlighting regeneration and the guidance response of peripheral neurons to gradients of NGF have not been systematically Irina Vetter,1, * Zac Pujic,1, * and Geoffrey J. Goodhill1,2 Abstract Directed sensory axon regeneration

  19. The Influence of Random Element Displacement on DOA Estimates Obtained with (Khatri–Rao-)Root-MUSIC

    PubMed Central

    Inghelbrecht, Veronique; Verhaevert, Jo; van Hecke, Tanja; Rogier, Hendrik

    2014-01-01

    Although a wide range of direction of arrival (DOA) estimation algorithms has been described for a diverse range of array configurations, no specific stochastic analysis framework has been established to assess the probability density function of the error on DOA estimates due to random errors in the array geometry. Therefore, we propose a stochastic collocation method that relies on a generalized polynomial chaos expansion to connect the statistical distribution of random position errors to the resulting distribution of the DOA estimates. We apply this technique to the conventional root-MUSIC and the Khatri-Rao-root-MUSIC methods. According to Monte-Carlo simulations, this novel approach yields a speedup by a factor of more than 100 in terms of CPU-time for a one-dimensional case and by a factor of 56 for a two-dimensional case. PMID:25393783

  20. Neurotrophic and neuroprotective actions of Achyranthes bidentata polypeptides on cultured dorsal root ganglia of rats and on crushed common peroneal nerve of rabbits.

    PubMed

    Cheng, Qiong; Yuan, Ying; Sun, Changnan; Gu, Xiaosong; Cao, Zheng; Ding, Fei

    2014-03-01

    We have isolated Achyranthes bidentata Blume polypeptides (ABPP) from the aqueous extract of A. bidentata Blume, a traditional Chinese medicine with multiple therapeutic applications. In this study, we aimed to investigate neurotrophic effects of ABPP on cultured dorsal root ganglia (DRGs) of rats and neuroprotective effects on crushed common peroneal nerve of rabbits. Immunochemistry and Western blot analysis indicated that ABPP (0.01, 0.1, and 1.0 ?g/ml) encouraged neurite outgrowth from cultured DRG explants/neurons in a concentration-dependent manner through activation of ERK1/2. After crush injury to rabbit common peroneal nerve, animals received daily administration of ABPP for 5 weeks. Electrophysiological assessments and histomorphological evaluation showed that 6.0mg/kg ABPP significantly enhanced nerve regeneration and function restoration. Our findings suggest that ABPP could be used as a neurotrophic and neuroprotective agent to treat peripheral nerve crush injury. PMID:24361134

  1. Translaminar Microendoscopic Herniotomy for Cranially Migrated Lumbar Disc Herniations Encroaching on the Exiting Nerve Root in the Preforaminal and Foraminal Zones

    PubMed Central

    Tono, Osamu; Senba, Hideyuki; Kitamura, Takahiro; Komiya, Norihiro; Oga, Masayoshi; Shidahara, Satoshi

    2013-01-01

    Study Design Case series. Purpose The aim of this study was to describe translaminar microendoscopic herniotomy (TL-MEH) for cranially migrated lumbar disc herniations encroaching on the exiting nerve root in the preforaminal and foraminal zones and to report preliminary results of the procedure. Overview of Literature Conventional interlaminar approaches for preforaminal and foraminal lumbar disc herniations result in extensive removal of the lamina and facet joint to remove disc fragments safely. More destructive approaches increase the risk of postoperative segmental instability. Methods TL-MEH is a minimally invasive procedure for herniotomy via the translaminar approach using a microendoscopic technique. TL-MEH was performed in seven patients with a cranially migrated lumbar disc herniation encroaching on the exiting nerve root. The disc fragments were located in the preforaminal zone in four patients, and in the preforaminal and foraminal zones in three. Results All patients experienced immediate relief from symptoms after surgery and satisfactory results at the final follow-up. Surgical complications, such as a dural tear, nerve injury, and surgical site infection, were not investigated. Conclusions TL-MEH seemed to be an effective and safe alternative minimally invasive surgical option for patients with a cranially migrated lumbar disc herniation encroaching the exiting nerve root in the preforaminal and foraminal zones. PMID:24066214

  2. Characterization of Thoracic Motor and Sensory Neurons and Spinal Nerve Roots in Canine Degenerative Myelopathy, a Potential Disease Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Morgan, Brandie R.; Coates, Joan R.; Johnson, Gayle C.; Shelton, G. Diane; Katz, Martin L.

    2014-01-01

    Canine Degenerative Myelopathy (DM) is a progressive adult-onset multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced stage DM. To determine if other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MN) and dorsal root ganglia (DRG), and in motor and sensory nerve root axons from DM-affected Boxers and Pembroke Welsh Corgis (PWCs). No alterations in MNs, or motor root axons were observed in either breed. However, advanced stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, or of their axons. Axonal loss in thoracic sensory roots and sensory nerve death suggest sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  3. Monocyte Traffic, Dorsal Root Ganglion Histopathology, and Loss of Intraepidermal Nerve Fiber Density in SIV Peripheral Neuropathy.

    PubMed

    Lakritz, Jessica R; Bodair, Ayman; Shah, Neal; O'Donnell, Ryan; Polydefkis, Michael J; Miller, Andrew D; Burdo, Tricia H

    2015-07-01

    HIV-associated sensory neuropathy remains the most common neurological complication of HIV infection and is characterized by dorsal root ganglion (DRG) inflammation and intraepidermal nerve fiber density (IENFD) loss. Chronic peripheral immune cell activation and accumulation may cause damage to the DRG, but has not been fully investigated yet. By using an SIV-infected, CD8-lymphocyte-depleted rhesus macaque model, we defined immune cells surrounding DRG neurons and their role in DRG pathology, measured cell traffic from the bone marrow to the DRGs using 5-bromo-2-deoxyuridine (BrdU) pulse, and serially measured IENFD. We found an increase in CD68(+) and CD163(+) macrophages in DRGs of SIV-infected animals. MAC387(+) recently recruited monocytes/macrophages were increased, along with BrdU(+) cells, in the DRGs of SIV-infected macaques. We demonstrated that 78.1% of all BrdU(+) cells in DRGs were also MAC387(+). The number of BrdU(+) monocytes correlated with severe DRG histopathology, which included neuronophagia, neuronal loss, and Nageotte nodules. These data demonstrate that newly recruited MAC387(+)BrdU(+) macrophages may play a significant role in DRG pathogenesis. IENFD decreased early (day 21), consistent with the development of sensory neuropathy in SIV-infected macaques. Decreased IENFD was associated with elevated BrdU(+) cells in the DRG. These data suggest that increased recruitment of macrophages to DRG is associated with severe DRG histopathology and IENFD loss. PMID:25956030

  4. Effects of selective spinal nerve ligation on acetic acid-induced nociceptive responses and ASIC3 immunoreactivity in the rat dorsal root ganglion

    Microsoft Academic Search

    Megumi Omori; Masataka Yokoyama; Yoshikazu Matsuoka; Hiroyuki Kobayashi; Satoshi Mizobuchi; Yoshitaro Itano; Kiyoshi Morita; Hiroyuki Ichikawa

    2008-01-01

    We investigated changes in pain behavior after injection of acetic acid in the hindpaws of rats with L5 spinal nerve ligation (SNL)-induced neuropathy. We also examined immunoreactivity for acid-sensing ion channel 3 (ASIC3) in the dorsal root ganglion (DRG) of rats with L5 SNL. Two weeks after SNL, the withdrawal threshold to a mechanical stimulus was significantly lower in the

  5. Multi-scale simulations predict responses to non-invasive nerve root stimulation

    NASA Astrophysics Data System (ADS)

    Laakso, Ilkka; Matsumoto, Hideyuki; Hirata, Akimasa; Terao, Yasuo; Hanajima, Ritsuko; Ugawa, Yoshikazu

    2014-10-01

    Objective. Established biophysical neurone models have achieved limited success in reproducing electrophysiological responses to non-invasive stimulation of the human nervous system. This is related to our insufficient knowledge of the induced electric currents inside the human body. Despite the numerous research and clinical applications of non-invasive stimulation, it is still unclear which internal sites are actually affected by it. Approach. We performed multi-scale computer simulations that, by making use of advances in computing power and numerical algorithms, combine a microscopic model of electrical excitation of neurones with a macroscopic electromagnetic model of the realistic whole-body anatomy. Main results. The simulations yield responses consistent with those experimentally recorded following magnetic and electrical motor root stimulation in human subjects, and reproduce the observed amplitudes and latencies for a wide variety of stimulation parameters. Significance. Our findings demonstrate that modern computational techniques can produce detailed predictions about which and where neurones are activated, leading to improved understanding of the physics and basic mechanisms of non-invasive stimulation and enabling potential new applications that make use of improved targeting of stimulation.

  6. Nerve injury induces a Gem-GTPase-dependent downregulation of P/Q-type Ca2+ channels contributing to neurite plasticity in dorsal root ganglion neurons.

    PubMed

    Scamps, Frédérique; Sangari, Sina; Bowerman, Melissa; Rousset, Mathieu; Bellis, Michel; Cens, Thierry; Charnet, Pierre

    2015-02-01

    Small RGK GTPases, Rad, Gem, Rem1, and Rem2, are potent inhibitors of high-voltage-activated (HVA) Ca(2+) channels expressed in heterologous expression systems. However, the role of this regulation has never been clearly demonstrated in the nervous system. Using transcriptional analysis, we show that peripheral nerve injury specifically upregulates Gem in mice dorsal root ganglia. Following nerve injury, protein expression was increased in ganglia and peripheral nerve, mostly under its phosphorylated form. This was confirmed in situ and in vitro in dorsal root ganglia sensory neurons. Knockdown of endogenous Gem, using specific small-interfering RNA (siRNA), increased the HVA Ca(2+) current only in the large-somatic-sized neurons. Combining pharmacological analysis of the HVA Ca(2+) currents together with Gem siRNA-transfection of larger sensory neurons, we demonstrate that only the P/Q-type Ca(2+) channels were enhanced. In vitro analysis of Gem affinity to various CaV?x-CaV2.x complexes and immunocytochemical studies of Gem and CaV? expression in sensory neurons suggest that the specific inhibition of the P/Q channels relies on both the regionalized upregulation of Gem and the higher sensitivity of the endogenous CaV2.1-CaV?4 pair in a subset of sensory neurons including the proprioceptors. Finally, pharmacological inhibition of P/Q-type Ca(2+) current reduces neurite branching of regenerating axotomized neurons. Taken together, the present results indicate that a Gem-dependent P/Q-type Ca(2+) current inhibition may contribute to general homeostatic mechanisms following a peripheral nerve injury. PMID:24809506

  7. Monitoring of immune cell response to B cell depletion therapy and nerve root injury using SPIO enhanced MRI

    NASA Astrophysics Data System (ADS)

    Thorek, Daniel L.

    2009-12-01

    Magnetic resonance (MR) is a robust platform for non-invasive, high-resolution anatomical imaging. However, MR imaging lacks the requisite sensitivity and contrast for imaging at the cellular level. This represents a clinical impediment to greater diagnostic accuracy. Recent advances have allowed for the in vivo visualization of populations and even of individual cells using superparamagnetic iron oxide (SPIO) MR contrast agents. These nanoparticles, commonly manifested as a core of a single iron oxide crystal or cluster of crystals coated in a biocompatible shell, function to shorten proton relaxation times. In MR imaging these constructs locally dephase protons, resulting in a decrease in signal (hypointensity) localized to the region of accumulation of SPIO. In the context of immune cell imaging, SPIO can provide insight into the cellular migration patterns, trafficking, temporal dynamics and progression of diseases and their related pathological states. Furthermore, by visualizing the presence and activity of immune cells, SPIO-enabled cellular imaging can help evaluate the efficacy of therapy in immune disorders. This thesis examines the production, modification and application of SPIO in a range of in vitro and in vivo immune-response-relevant cellular systems. The role of different nanoparticle characteristics including diameter, surface charge and concentration are investigated in the labeling of T cells in culture. Following optimization of SPIO loading conditions for lymphocytes, the effect these particles have on the activation of primary B cells are elucidated. B cells are tracked using a variety of modalities, with and without the application of B cell depleting therapy. This is to evaluate the efficacy of SPIO as in vivo marker for B cell distribution. Unmodified SPIO were applied to monitor macrophage infiltration in a transient nerve root compression model, with implications for neck pain diagnosis and treatment. Nanoparticle accumulation and MR hypointensity was correlated to the presence of activated macrophage at the site of injury. Taken together, the application of SPIO to study nanoparticle uptake in vitro and visualization of immune cells in vivo provide a basis for advanced study and diagnosis of diverse pathologies.

  8. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  9. Contribution of TRPV1 receptor-expressing fibers to spinal ventral root after-discharges and mechanical hyperalgesia in a spared nerve injury (SNI) rat model.

    PubMed

    Yamamoto, Shohei; Ohsawa, Masahiro; Ono, Hideki

    2013-01-01

    Neuropathic pain induces allodynia and hyperalgesia. In the spared nerve injury (SNI) model, marked mechanical hyperalgesia is manifested as prolongation of the duration of paw withdrawal after pin stimulation. We have previously reported that spinal ventral root discharges (after-discharges) after cessation of noxious mechanical stimulation applied to the corresponding hindpaw were prolonged in anesthetized spinalized rats. Since these after-discharges occurred through transient receptor potential (TRP) V1-positive fibers, these fibers could contribute to mechanical hyperalgesia. Therefore, we examined whether selective deletion of TRPV1-positive fibers by resiniferatoxin, an ultrapotent TRPV1 agonist, would affect the behavioral changes and ventral root discharges in SNI rats. Mechanical allodynia in the von Frey test, mechanical hyperalgesia after pin stimulation, and enhancement of ventral root discharges, but not thermal hyperalgesia in the plantar test, appeared in Wistar rats with SNI. Mechanical hyperalgesia was abolished by treatment with resiniferatoxin, whereas mechanical allodynia was not affected. Moreover, resiniferatoxin eliminated after-discharges completely. These results show that TRPV1-positive fibers do not participate in the mechanical allodynia caused by sensitization of A?-fibers, but contribute to the enhancement of after-discharges and mechanical hyperalgesia following SNI. It is suggested that the mechanisms responsible for generating mechanical allodynia differ from those for prolongation of mechanical hyperalgesia. PMID:23238537

  10. Contralateral femoral nerve compression: An unrecognized complication after extreme lateral interbody fusion (XLIF).

    PubMed

    Papanastassiou, Ioannis D; Eleraky, Mohammad; Vrionis, Frank D

    2011-01-01

    Extreme lateral interbody fusion (XLIF) is a relatively new procedure for the treatment of degenerative disc disease avoiding the morbidity of anterior approaches. Ipsilateral L2-5 nerve root irritation and injury are well-described complications. We describe two patients with contralateral extremity symptoms, not reported so far. In the first patient the injury was caused by a displaced endplate fragment compressing the contralateral nerve root; in the second patient, the injury resulted from a far-lateral herniation after the XLIF procedure. Both patients experienced resolution of their symptoms after being reoperated. Overall, this complication was encountered in 2/32 levels treated during the study period. Overzealous endplate removal and breaking of the osteophytes in the opposite corner of the intervertebral disc, although desirable for maximal coronal deformity correction, may lead to irritation of the contralateral nerve roots. Attention is needed especially where the interbody cage is placed posteriorly or diagonally towards the neuralforamen. PMID:20965732

  11. Increased expression of HCN2 channel protein in L4 dorsal root ganglion neurons following axotomy of L5- and inflammation of L4-spinal nerves in rats.

    PubMed

    Smith, T; Al Otaibi, M; Sathish, J; Djouhri, L

    2015-06-01

    A hallmark of peripheral neuropathic pain (PNP) is chronic spontaneous pain and/or hypersensitivity to normally painful stimuli (hyperalgesia) or normally nonpainful stimuli (allodynia).This pain results partly from abnormal hyperexcitability of dorsal root ganglion (DRG) neurons. We have previously shown, using a modified version of the lumbar 5 (L5)-spinal nerve ligation model of PNP (mSNA model involving L5-spinal nerve axotomy plus loose ligation of the lumbar 4 (L4)-spinal nerve with neuroinflammation-inducing chromic-gut), that L4 DRG neurons exhibit increased spontaneous activity, the key characteristic of neuronal hyperexcitability. The underlying ionic and molecular mechanisms of the hyperexcitability of L4 DRG neurons are incompletely understood, but could result from changes in expression and/or function of ion channels including hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which are active near the neuron's resting membrane potential, and which produce an excitatory inward current that depolarizes the membrane potential toward the threshold of action potential generation. Therefore, in the present study we used the mSNA model to investigate whether: (a) expression of HCN1-HCN3 channels is altered in L4 DRG neurons which, in the mSNA model, are essential for transmission of the evoked pain, and which contribute to chronic spontaneous pain, and (b) local (intraplantar) blockade of these HCN channels, with a specific blocker, ZD7288, attenuates chronic spontaneous pain and/or evoked pain in mSNA rats. We found 7days after mSNA: (1) a significant increase in HCN2-immunoreactivity in small (<30?m) DRG neurons (predominantly IB4-negative neurons), and in the proportion of small neurons expressing HCN2 (putative nociceptors); (2) no significant change in HCN1- or HCN3-immunoreactivity in all cell types; and (3) attenuation, with ZD7288 (100?M intraplantar), of chronic spontaneous pain behavior (spontaneous foot lifting) and mechanical, but not, heat hypersensitivity. The results suggest that peripheral HCN channels contribute to mechanisms of spinal nerve injury-induced PNP, and that HCN channels, possibly HCN2, represent a novel target for PNP treatment. PMID:25813712

  12. Vascularization of the dorsal root ganglia and peripheral nerve of the mouse: Implications for chemical-induced peripheral sensory neuropathies

    Microsoft Academic Search

    Juan M Jimenez-Andrade; Monica B Herrera; Joseph R Ghilardi; Marina Vardanyan; Ohannes K Melemedjian; Patrick W Mantyh

    2008-01-01

    Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent

  13. A diagnosis challenge-L4 nerve root compression as the initial presentation of chronic inflammatory demyelinating polyneuropathy.

    PubMed

    Cojocaru, Inimioara Mihaela; Alexianu, Marilena; Bastian, Alexandra; Sapira, Violeta; Her?ea, Cristina; Cojocaru, M

    2012-01-01

    The authors present the case of a 65-year-old woman who was admitted for paraparesis and paresthesias in the inferior limbs. The neurological examination revealed the difficulty in extension of the right foot and of the right toe, accompanied by paresthesias located in the anterolateral area of the right leg, dorsum and plantar area of the foot, the reduction of the right knee jerk, and of the ankle tendon jerk both sides. The vertebro-spinal MRI showed lumbar canal stenosis with L4 intraforaminal compression on the right, and L2-L3 on the left. CSF examination revealed mild increase in protein concentration. The morphological picture of the sural nerve biopsy was compatible with a chronic inflammatory neuropathy and severe muscular lesions of neurogenic origin were observed on right gastrocnemius muscle biopsy. The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) was established. Solu-medrol (0.5 g/d)-5 days, then medrol (prednisolone) was done, followed by improving of the symptomatology. For the relapse of the disease intravenous immunoglobulins (IVIG)-0.4 g/kg/d-5 days was the elective treatment. Six months later she presented a new relapse. IVIG were administered with the remission of the sensitive symptoms. A chronic treatment with medrol was recommended. The diagnosis of L4 disc herniation was obvious in the studied case, but the electroneurographic examination brought extra data for the associated diagnosis of CIDP whose onset was asymmetrical and initially paucisymptomatic. Neither the electroneurographic examination nor the CSF examination were total relevant for CIDP, imposing the sural nerve biopsy. The diagnosis of CIDP involves a team-work composed of neurologist, electroneurophysiologist and neuropathologist. PMID:23610977

  14. Effects of sciatic nerve transection on glucose uptake in the presence and absence of lactate in the frog dorsal root ganglia and spinal cord.

    PubMed

    Rigon, F; Horst, A; Kucharski, L C; Silva, R S M; Faccioni-Heuser, M C; Partata, W A

    2014-08-01

    Frogs have been used as an alternative model to study pain mechanisms because the simplicity of their nervous tissue and the phylogenetic aspect of this question. One of these models is the sciatic nerve transection (SNT), which mimics the clinical symptoms of "phantom limb", a condition that arises in humans after amputation or transverse spinal lesions. In mammals, the SNT increases glucose metabolism in the central nervous system, and the lactate generated appears to serve as an energy source for nerve cells. An answerable question is whether there is elevated glucose uptake in the dorsal root ganglia (DRG) after peripheral axotomy. As glucose is the major energy substrate for frog nervous tissue, and these animals accumulate lactic acid under some conditions, bullfrogs Lithobates catesbeianus were used to demonstrate the effect of SNT on DRG and spinal cord 1-[14C] 2-deoxy-D-glucose (14C-2-DG) uptake in the presence and absence of lactate. We also investigated the effect of this condition on the formation of 14CO2 from 14C-glucose and 14C-L-lactate, and plasmatic glucose and lactate levels. The 3-O-[14C] methyl-D-glucose (14C-3-OMG) uptake was used to demonstrate the steady-state tissue/medium glucose distribution ratio under these conditions. Three days after SNT, 14C-2-DG uptake increased, but 14C-3-OMG uptake remained steady. The increase in 14C-2-DG uptake was lower when lactate was added to the incubation medium. No change was found in glucose and lactate oxidation after SNT, but lactate and glucose levels in the blood were reduced. Thus, our results showed that SNT increased the glucose metabolism in the frog DRG and spinal cord. The effect of lactate on this uptake suggests that glucose is used in glycolytic pathways after SNT. PMID:25627385

  15. Extracellular Nm23H1 stimulates neurite outgrowth from dorsal root ganglia neurons in vitro independently of nerve growth factor supplementation or its nucleoside diphosphate kinase activity

    SciTech Connect

    Wright, K.T. [Keele University at the RJAH Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom)] [Keele University at the RJAH Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom); Seabright, R.; Logan, A. [Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, Birmingham University, Birmingham (United Kingdom)] [Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, Birmingham University, Birmingham (United Kingdom); Lilly, A.J.; Khanim, F.; Bunce, C.M. [Biosciences, Birmingham University, Birmingham (United Kingdom)] [Biosciences, Birmingham University, Birmingham (United Kingdom); Johnson, W.E.B., E-mail: w.e.johnson@aston.ac.uk [Life and Health Sciences, Aston University, Birmingham (United Kingdom)] [Life and Health Sciences, Aston University, Birmingham (United Kingdom)

    2010-07-16

    Research highlights: {yields} Extracellular Nm23H1 stimulates nerve growth. {yields} Extracellular Nm23H1 provides pathfinding cues to growth cones. {yields} The neurotrophic activity of Nm23H1 is independent of NDP kinase activity. {yields} The neurotrophic activity of Nm23H1 is independent of NGF. -- Abstract: The nucleoside diphosphate (NDP) kinase, Nm23H1, is a highly expressed during neuronal development, whilst induced over-expression in neuronal cells results in increased neurite outgrowth. Extracellular Nm23H1 affects the survival, proliferation and differentiation of non-neuronal cells. Therefore, this study has examined whether extracellular Nm23H1 regulates nerve growth. We have immobilised recombinant Nm23H1 proteins to defined locations of culture plates, which were then seeded with explants of embryonic chick dorsal root ganglia (DRG) or dissociated adult rat DRG neurons. The substratum-bound extracellular Nm23H1 was stimulatory for neurite outgrowth from chick DRG explants in a concentration-dependent manner. On high concentrations of Nm23H1, chick DRG neurite outgrowth was extensive and effectively limited to the location of the Nm23H1, i.e. neuronal growth cones turned away from adjacent collagen-coated substrata. Nm23H1-coated substrata also significantly enhanced rat DRG neuronal cell adhesion and neurite outgrowth in comparison to collagen-coated substrata. These effects were independent of NGF supplementation. Recombinant Nm23H1 (H118F), which does not possess NDP kinase activity, exhibited the same activity as the wild-type protein. Hence, a novel neuro-stimulatory activity for extracellular Nm23H1 has been identified in vitro, which may function in developing neuronal systems.

  16. Changes in expression of sensory organ-specific microRNAs in rat dorsal root ganglia in association with mechanical hypersensitivity induced by spinal nerve ligation

    PubMed Central

    Aldrich, Benjamin T.; Frakes, Eli P.; Kasuya, Junko; Hammond, Donna L.; Kitamoto, Toshihiro

    2009-01-01

    Chronic neuropathic pain caused by peripheral nerve injury is associated with global changes in gene expression in damaged neurons. To understand the molecular mechanisms underlying neuropathic pain, it is essential to elucidate how nerve injury alters gene expression and how the change contributes to the development and maintenance of chronic pain. MicroRNAs are non-protein-coding RNA molecules that regulate gene expression in a wide variety of biological processes mainly at the level of translation. This study investigated the possible involvement of microRNAs in gene regulation relevant to neuropathic pain. The analyses focused on a sensory organ-specific cluster of microRNAs that includes miR-96, -182, and -183. RT-PCR analyses confirmed that these microRNAs were highly enriched in the dorsal root ganglion (DRG) of adult rats. Using the L5 spinal nerve ligation (SNL) model of chronic neuropathic pain, we observed a significant reduction in expression of these microRNAs in injured DRG neurons compared to controls. In situ hybridization and immunohistochemical analyses revealed that these microRNAs are expressed in both myelinated (N52 positive) and unmyelinated (IB4 positive) primary afferent neurons. They also revealed that the intracellular distributions of the microRNAs in DRG neurons were dramatically altered in animals with mechanical hypersensitivity. Whereas microRNAs were uniformly distributed within the DRG soma of non-allodynic animals, they were preferentially localized to the periphery of neurons in allodynic animals. The redistribution of microRNAs was associated with changes in the distribution of the stress granule protein TIA-1. These data demonstrate that SNL induces changes in expression levels and patterns of miR-96, -182, and -183, implying their possible contribution to chronic neuropathic pain through translational regulation of pain-relevant genes. Moreover, stress granules were suggested to be assembled and associated with microRNAs after SNL, which may play a role in modification of microRNA-mediated gene regulation in DRG neurons. PMID:19699278

  17. Contralateral femoral nerve compression: An unrecognized complication after extreme lateral interbody fusion (XLIF)

    Microsoft Academic Search

    Ioannis D. Papanastassiou; Mohammad Eleraky; Frank D. Vrionis

    2011-01-01

    Extreme lateral interbody fusion (XLIF) is a relatively new procedure for the treatment of degenerative disc disease avoiding the morbidity of anterior approaches. Ipsilateral L2–5 nerve root irritation and injury are well-described complications. We describe two patients with contralateral extremity symptoms, not reported so far. In the first patient the injury was caused by a displaced endplate fragment compressing the

  18. De novo expression of Nav1.7 in injured putative proprioceptive afferents: Multiple tetrodotoxin-sensitive sodium channels are retained in the rat dorsal root after spinal nerve ligation.

    PubMed

    Fukuoka, T; Miyoshi, K; Noguchi, K

    2015-01-22

    Tetrodotoxin-sensitive (TTX-s) spontaneous activity is recorded from the dorsal roots after peripheral nerve injury. Primary sensory neurons in the dorsal root ganglion (DRG) express multiple TTX-s voltage-gated sodium channel ?-subunits (Navs). Since Nav1.3 increases, whereas all other Navs decrease, in the DRG neurons after peripheral nerve lesion, Nav1.3 is proposed to be critical for the generation of these spontaneous discharges and the contributions of other Navs have been ignored. Here, we re-evaluate the changes in expression of three other TTX-s Navs, Nav1.1, Nav1.6 and Nav1.7, in the injured 5th lumbar (L5) primary afferent components following L5 spinal nerve ligation (SNL) using in situ hybridization histochemistry and immunohistochemistry. While the overall signal intensities for these Nav mRNAs decreased, many injured DRG neurons still expressed these transcripts at clearly detectable levels. All these Nav proteins accumulated at the proximal stump of the ligated L5 spinal nerve. The immunostaining patterns of Nav1.6 and Nav1.7 associated with the nodes of Ranvier were maintained in the ipsilateral L5 dorsal root. Interestingly, putative proprioceptive neurons characterized by ?3 Na+/K+ ATPase-immunostaining specifically lacked Nav1.7 mRNA in naïve DRG but displayed de novo expression of this transcript following SNL. Nav1.7-immunoreactive fibers were significantly increased in the ipsilateral gracile nucleus where central axonal branches of the injured A-fiber afferents terminated. These data indicate that multiple TTX-s channel subunits could contribute to the generation and propagation of the spontaneous discharges in the injured primary afferents. Specifically, Nav1.7 may cause some functional changes in sensory processing in the gracile nucleus after peripheral nerve injury. PMID:25453779

  19. Deficits in foot skin sensation are related to alterations in balance control in chronic low back patients experiencing clinical signs of lumbar nerve root impingement.

    PubMed

    Frost, Lydia R; Bijman, Marc; Strzalkowski, Nicholas D J; Bent, Leah R; Brown, Stephen H M

    2015-05-01

    Chronic low back pain (LBP) patients with radiculopathy, or sciatica, experience pain, tingling or numbness radiating down their leg due to compression of the lumbar nerve root. The resulting reduction in somatosensory information from the foot sole may contribute to deficits in standing balance control. This work was designed to investigate the relationship between foot skin sensitivity and standing balance control in chronic LBP patients with associated radiculopathy. Patients (n=9) and matched healthy controls (n=9) were recruited to the study, and were tested for balance control in both quiet standing as well as during rapid arm raise perturbation trials on a force plate. Foot skin sensitivity was tested bilaterally for vibratory threshold (3, 40 and 250 Hz) and touch (monofilament) threshold. Results demonstrate that patients had reduced sensitivity to 250 Hz vibration in their affected compared to unaffected foot (at the great toe and heel), as well as compared to controls (at the great toe), but there were no differences with lower frequency vibratory testing or with monofilament testing. While there were no significant between-group differences in balance measures, moderate statistically significant correlations between 250 Hz sensitivity and quiet standing balance parameters were uncovered. Thus, patients demonstrate reduced high-frequency vibratory sensitivity at the foot sole, and correlations with quiet standing balance measures indicate a connection between these foot skin sensitivity deficits and alterations in balance control. Clinically, this identifies high frequency vibration testing as an important measure of skin sensitivity in patients with radiculopathy. PMID:25887249

  20. Evaluation of Behavior and Expression of Receptor Activator of Nuclear Factor-Kappa B Ligand in Dorsal Root Ganglia after Sciatic Nerve Compression and Application of Nucleus Pulposus in Rats

    PubMed Central

    Matsuyama, Yoshiyuki; Sakuma, Yoshihiro; Suzuki, Miyako; Orita, Sumihisa; Yamauchi, Kazuyo; Inoue, Gen; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Kubota, Gou; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Nakamura, Junichi; Toyone, Tomoaki; Takahashi, Kazuhisa

    2014-01-01

    Study Design Experimental animal study. Purpose To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. Overview of Literature The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats. Methods Mechanical hyperalgesia and RANKL expression were assessed in three groups of rats: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry. Results Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01). Conclusions The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP. PMID:25346807

  1. The effect of botulinum neurotoxin A on sciatic nerve injury-induced neuroimmunological changes in rat dorsal root ganglia and spinal cord.

    PubMed

    Mika, J; Rojewska, E; Makuch, W; Korostynski, M; Luvisetto, S; Marinelli, S; Pavone, F; Przewlocka, B

    2011-02-23

    Botulinum neurotoxin serotype A (BoNT/A) acts by cleaving synaptosome-associated-protein-25 (SNAP-25) in nerve terminals to inhibit neuronal release and shows long-lasting antinociceptive action in neuropathic pain. However, its precise mechanism of action remains unclear. Our study aimed to characterize BoNT/A-induced neuroimmunological changes after chronic constriction injury (CCI) of the sciatic nerve. In the ipsilateral lumbar spinal cords of CCI-exposed rats, the mRNA of microglial marker (complement component 1q, C1q), astroglial marker (glial fibrillary acidic protein, GFAP), and prodynorphin were upregulated, as measured by reverse transcription-polymerase chain reaction (RT-PCR). No changes appeared in mRNA for proenkephalin, pronociceptin, or neuronal and inducible nitric oxide synthase (NOS1 and NOS2, respectively). In the dorsal root ganglia (DRG), an ipsilateral upregulation of prodynorphin, pronociceptin, C1q, GFAP, NOS1 and NOS2 mRNA and a downregulation of proenkephalin mRNA were observed. A single intraplantar BoNT/A (75 pg/paw) injection induced long-lasting antinociception in this model. BoNT/A diminished the injury-induced ipsilateral spinal upregulation of C1q mRNA. In the ipsilateral DRG a significant decrease of C1q-positive cell activation and of the upregulation of prodynorphin, pronociceptin and NOS1 mRNA was also observed following BoNT/A admistration. BoNT/A also diminished the injury-induced upregulation of SNAP-25 expression in both structures. We provide evidence that BoNT/A impedes injury-activated neuronal function in structures distant from the injection site, which is demonstrated by its influence on NOS1, prodynorphin and pronociceptin mRNA levels in the DRG. Moreover, the silence of microglia/macrophages after BoNT/A administration could be secondary to the inhibition of neuronal activity, but this decrease in neuroimmune interactions could be the key to the long-lasting BoNT/A effect on neuropathic pain. PMID:21111791

  2. Cranial and Spinal Nerve Organization in Amphioxus and Lampreys: Evidence for an Ancestral Craniate Pattern

    Microsoft Academic Search

    B. Fritzsch; Glenn Northcutt

    1993-01-01

    The spinal nerves in amphioxus are compared with the spinal and cranial nerves in lampreys. The dorsal spinal roots in amphioxus are similar to the mixed sensory and motor dorsal roots of many cranial nerves in lampreys but not to the purely sensory dorsal spinal roots in lampreys and gnathostomes. Likewise, cranial nerves V, VII, IX and X in lampreys,

  3. Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double-blind sham-controlled study.

    PubMed

    Gallas, S; Gourcerol, G; Ducrotté, P; Mosni, G; Menard, J-F; Michot, F; Leroi, A-M

    2009-04-01

    Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short-term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min(-1) for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high-amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8-39) after Bisacodyl administration during active stimulation compared to 14 min (range 5-40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl-induced colonic contractions. PMID:19126187

  4. An Evaluation of the Effectiveness of Hyaluronidase in the Selective Nerve Root Block of Radiculopathy: A Double Blind, Controlled Clinical Trial

    PubMed Central

    Ko, Sang-Bong; Vaccaro, Alexander R; Shin, Dong-Young

    2015-01-01

    Study Design Prospective, double-blind, randomized controlled trial. Purpose To determine the ability of hyaluronidase to provide longer lasting pain relief and functional improvement in patients with lumbar radiculopathy. Overview of Literature Selective nerve root block (SNRB) is a good treatment option in lumbar radiculopathy. We studied the effectiveness of hyaluronidase when added to the traditional SNRB regimen. Methods A sample size of 126 patients per group was necessary. A sample of 252 patients who underwent an injection procedure with or without hyaluronidase due to radiculopathy was included in this study. The patients were randomly divided into two groups: the control (C) group and the hyaluronidase (H) group. After SNRB due to radiculopathy, the visual analog scale (VAS) was compared at 2, 4, 6, 8, and 12 weeks between the two groups, and the Oswestry disability index (ODI) was compared at 12 weeks between the two groups. Results Both groups seemed to have general improvement in VAS, but in C group, the VAS was higher than the H group 2 and 4 weeks after the surgery, and the difference in time-group change between 2 groups was statistically significant (p <0.05). ODI improved in both groups, and the difference in time-group change between 2 groups was not statistically significant (p >0.05). Conclusions The rebound pain (the re-occurrence of pain within 2-4 weeks after injection) that occurs within 2-4 weeks after the injection of the routine regimen can be reduced when hyaluronidase is added to the routine SNRB regimen. PMID:25705339

  5. Anatomical variation of sciatic nerve division in the popliteal fossa and its implication in popliteal nerve blockade

    Microsoft Academic Search

    Folia Morphol; H. A. M. Saleh; M. M. O. El-fark; G. A. Abdel-Hamid

    The sciatic nerve (SN) originates from the L4-S3 roots in the form of two nerve trunks: the tibial nerve (TN) and the common peroneal nerve (CPN). The TN and CPN are encompassed by a single epineural sheath and eventually sepa- rate (divide) in the popliteal fossa. This division of the SN occurs at a variable level above the knee and

  6. Aluminum and calcium distribution patterns in aluminum-intoxicated roots of Allium cepa do not support the calcium-displacement hypothesis and indicate signal-mediated inhibition of root growth

    Microsoft Academic Search

    R. M. S. Schofield; J. Pallon; G. Fiskesjö; G. Karlsson; K. G. Malmqvist

    1998-01-01

    .   The aluminum and calcium distributions in the root tips of aluminum-intoxicated onions, Allium cepa L., were mapped using PIXE (particle-induced X-ray emission) microanalysis. Not enough aluminum was present to have replaced,\\u000a atom-for-atom, more than a minor fraction of the calcium. Furthermore, no inverse relationship between variations in aluminum\\u000a and calcium concentrations was observed for pairs of adjacent 30-?m-diameter regions.

  7. Regeneration in Spinal Neurons: Proteosynthesis Following Nerve Growth Factor Administration

    Microsoft Academic Search

    Donald Scott Jr.; Ernest Gutmann; Peter Horsky

    1966-01-01

    Incorporation of H3-leucine into dorsal root ganglion cells in rats was markedly increased over that of controls following section of sciatic and femoral nerves. Crush lesion of dorsal roots did not increase the H3-leucine uptake of these cells except in animals which had received nerve growth factor after the operation.

  8. [Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 2: intraplexal nerve transfers].

    PubMed

    Robla-Costales, J; Socolovsky, M; Di Masi, G; Robla-Costales, D; Domitrovic, L; Campero, A; Fernández-Fernández, J; Ibáñez-Plágaro, J; García-Cosamalón, J

    2011-12-01

    After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In a previous paper extraplexual nerve transfers were analyzed; this literature review complements the preceding paper analyzing intraplexual nerve transfers, and thus completing the analysis of the nerve transfers available in brachial plexus surgery. PMID:22167282

  9. Optic Nerve Drusen

    MedlinePLUS

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Drusen En Español Read in Chinese What are optic nerve drusen? Optic nerve drusen are abnormal globular ...

  10. [Extreme lateral lumbar intervertebral disk displacement. Incidence, symptoms and therapy].

    PubMed

    Ebeling, U; Mattle, H; Reulen, H J

    1990-04-01

    Upper lumbar nerve root compression or a femoralgia is often caused by extreme lateral lumbar disc herniation. This type of lumbar disc herniation compresses the nerve root inside or laterally to the intervertebral canal, while mediolateral disc herniations squeeze it in the lateral recess. Pain radiating obliquely over the thigh is the dominant clinical symptom. Bending the body to the ipsilateral side usually increases the pain. When neurologic signs are present, motor deficits tend to be more prominent than sensory and the deficits never affect more than one nerve root. Most frequently a weakness of knee extension occurs. PMID:2191229

  11. Peripheral Nerve Disorders

    MedlinePLUS

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  12. [Nerve reconstruction techniques in traumatic brachial plexus surgery. Part 1: extraplexal nerve transfers].

    PubMed

    Robla-Costales, J; Socolovsky, M; Di Masi, G; Domitrovic A Campero J Fernández-Fernández J Ibáñez-Plágaro J García-Cosamalón, L; Campero, A; Fernández-Fernández, J; Ibáñez-Plágaro, J; García-Cosamalón, J

    2011-12-01

    After the great enthusiasm generated in the '70s and '80s in brachial plexus surgery as a result of the incorporation of microsurgical techniques and other advances, brachial plexus surgery has been shaken in the last two decades by the emergence of nerve transfer techniques or neurotizations. This technique consists in sectioning a donor nerve, sacrificing its original function, to connect it with the distal stump of a receptor nerve, whose function was lost during the trauma. Neurotizations are indicated when direct repair is not possible, i.e. when a cervical root is avulsed at its origin in the spinal cord. In recent years, due to the positive results of some of these nerve transfer techniques, they have been widely used even in some cases where the roots of the plexus were preserved. In complete brachial plexus injuries, it is mandatory to determine the exact number of roots available (not avulsed) to perform a direct reconstruction. In case of absence of available roots, extraplexual nerve transfers are employed, such as the spinal accessory nerve, the phrenic nerve, the intercostal nerves, etc., to increase the amount of axons transferred to the injured plexus. In cases of avulsion of all the roots, extraplexal neurotizations are the only reinnervation option available to limit the long-term devastating effects of this injury. Given the large amount of reports that has been published in recent years regarding brachial plexus traumatic injuries, the present article has been written in order to clarify the concerned readers the indications, results and techniques available in the surgical armamentarium for this condition. Since the choice of either surgical technique is usually taken during the course of the procedure, all this knowledge should be perfectly embodied by the surgical team before the procedure. In this first part extraplexual nerve transfers are analyzed, while intraplexual nerve transfers will be analyzed in the second part of this presentation. PMID:22167281

  13. Bladder reinnervation using a primarily motor donor nerve (femoral nerve branches) is functionally superior to using a primarily sensory donor nerve (genitofemoral nerve)

    PubMed Central

    Gomez-Amaya, Sandra M.; Barbe, Mary F.; Brown, Justin M.; Lamarre, Neil S.; Braverman, Alan S.; Massicotte, Vicky S.; Ruggieri, Michael R.

    2014-01-01

    Purpose To determine whether transfer of a primarily motor nerve (Femoral, F) to the anterior vesicle branch of the pelvic nerve (PN) allows more effective bladder reinnervation than a primarily sensory nerve (genitofemoral, GF). Methods Forty-one female mongrel hounds underwent bladder decentralization, decentralization and then bilateral nerve transfer (GFNT and FNT) or were sham/unoperated controls. Decentralization was achieved by bilateral transection of all sacral roots that induce bladder contractions upon electrical stimulation. The retrograde neuronal labeling dye fluorogold was injected into the bladder 3 weeks prior to euthanasia. Results Increased detrusor pressure after direct stimulation of the transferred nerve, lumbar spinal cord or spinal roots was observed in 12/17 GFNT dogs (mean detrusor pressure = 7.6±1.4 cmH2O) and in 9/10 FNT-V dogs (mean detrusor pressure = 11.7±3.1 cm H2O). The mean detrusor pressures after direct electrical stimulation of transferred femoral nerves were statistically significantly greater than after stimulation of the transferred genitofemoral nerves. Retrogradely labeled neurons from the bladder observed in upper lumbar cord segments after GFNT and FNT confirmed bladder reinnervation as did labeled axons at the nerve transfer site. Conclusions While transfer of either a mixed sensory and motor nerve (GFN) or a primarily motor nerve (FN) can reinnervate the bladder, using a primarily motor nerve provides greater return of nerve-evoked detrusor contraction. This surgical approach may be useful for patients with lower motor spinal cord injury to accomplish bladder emptying. PMID:25066874

  14. A precision mechanical nerve stimulator

    NASA Astrophysics Data System (ADS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1988-11-01

    An electromechanical device, used to apply and monitor stimulating pulses to a mammalian motor nerve, has been successfully developed at NASA Langley Research Center. Two existing force transducers, a flight skin friction balance and a miniature skin friction balance which were designed for making aerodynamic drag measurements, were modified and incorporated to form this precision instrument. The nerve stimulator is a type one servomechanism capable of applying and monitoring stimulating pulses of 0 to 10 grams with a precision of better than +/- 0.05 grams. Additionally, the device can be independently used to apply stimulating pulses by displacing the nerve from 0 to 0.25 mm with a precision of better than +/- 0.001 mm while measuring the level of the load applied.

  15. Transitional Nerve: A New and Original Classification of a Peripheral Nerve Supported by the Nature of the Accessory Nerve (CN XI)

    PubMed Central

    Benninger, Brion; McNeil, Jonathan

    2010-01-01

    Classically, the accessory nerve is described as having a cranial and a spinal root. Textbooks are inconsistent with regard to the modality of the spinal root of the accessory nerve. Some authors report the spinal root as general somatic efferent (GSE), while others list a special visceral efferent (SVE) modality. We investigated the comparative, anatomical, embryological, and molecular literature to determine which modality of the accessory nerve was accurate and why a discrepancy exists. We traced the origin of the incongruity to the writings of early comparative anatomists who believed the accessory nerve was either branchial or somatic depending on the origin of its target musculature. Both theories were supported entirely by empirical observations of anatomical and embryological dissections. We find ample evidence including very recent molecular experiments to show the cranial and spinal root are separate entities. Furthermore, we determined the modality of the spinal root is neither GSE or SVE, but a unique peripheral nerve with a distinct modality. We propose a new classification of the accessory nerve as a transitional nerve, which demonstrates characteristics of both spinal and cranial nerves. PMID:21318044

  16. Clarifying the nomenclature of intervertebral disc degeneration and displacement: from bench to bedside.

    PubMed

    Wang, Hai-Qiang; Samartzis, Dino

    2014-01-01

    As a significant determinant of low back pain, intervertebral disc degeneration (IDD) has attracted more and more attention of both investigators and physicians. Disc herniation, termed as intervertebral disc displacement, is amongst the most prevalent spinal diseases closely linked with IDD. Due to the same origins and similar pathophysiology, the ambiguity regarding the similarity and difference of IDD and intervertebral disc displacement thus remains. The aim of this study was to clarify the nomenclature of IDD and disc herniation in terms of molecular etiology, pathophysiology, nature history and clinical outcomes. Collectively, IDD is a type of multifaceted, progressive spinal disease with or without clinical symptoms as back pain, characterized by extracellular matrix and the integrity of NP and AF lost, fissures formation. Disc herniation (termed as intervertebral disc displacement) is a type of spinal disease based on IDD or not, with local pain and/or sciatica due to mechanical compression and autoimmune cascades upon the corresponding nerve roots. Clarifying the nomenclature of intervertebral disc degeneration and displacement has important implications both for investigators and for physicians. PMID:24817926

  17. Suprascapular nerve release for treatment of shoulder and periscapular pain following intracranial spinal accessory nerve injury.

    PubMed

    Flores, Leandro Pretto

    2008-11-01

    Iatrogenic injury to the spinal accessory nerve is one of the most common causes of trapezius muscle palsy. Dysfunction of this muscle can be a painful and disabling condition because scapular winging may impose traction on the soft tissues of the shoulder region, including the suprascapular nerve. There are few reports regarding therapeutic options for an intracranial injury of the accessory nerve. However, the surgical release of the suprascapular nerve at the level of the scapular notch is a promising alternative approach for treatment of shoulder pain in these cases. The author reports on 3 patients presenting with signs and symptoms of unilateral accessory nerve injury following resection of posterior fossa tumors. A posterior approach was used to release the suprascapular nerve at the level of the scapular notch, transecting the superior transverse scapular ligament. All patients experienced relief of their shoulder and scapular pain following the decompressive surgery. In 1 patient the primary dorsal branch of the C-2 nerve root was transferred to the extracranial segment of the accessory nerve, and in the other 2 patients a tendon transfer (the Eden-Lange procedure) was used. Results from this report show that surgical release of the suprascapular nerve is an effective treatment for shoulder and periscapular pain in patients who have sustained an unrepairable injury to the accessory nerve. PMID:18976092

  18. Composite nerve fibers in the hypogastric and pelvic splanchnic nerves: an immunohistochemical study using elderly cadavers

    PubMed Central

    Jang, Hyung Suk; Hieda, Keisuke; Kim, Ji Hyun; Murakami, Gen; Abe, Shin-ichi; Matsubara, Akio

    2015-01-01

    To determine the proportion of nerve fibers in the hypogastric nerve (HGN) and pelvic splanchnic nerve (PSN), small tissue strips of the HGN and PSN from 12 donated elderly cadavers were examined histologically. Immunohistochemistry for neuronal nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH) was performed. More than 70% of fibers per bundle in the HGN were positive for TH at the level of the sacral promontory. In addition, NOS- (negative) and/or VIP+ (positive) fibers were observed in small areas of each nerve bundle, although the proportion of each was usually less than 10%. In the PSN near the third sacral nerve root, the proportion of nerve fibers positive for NOS and/or VIP (or TH) was below 30%. In both the HGN and PSN, the number of VIP+ fibers was usually greater than that of NOS+ fibers, with frequent co-localization of NOS and VIP. More fibers in both nerves were positive for TH than for these other markers. In contrast to pelvic plexus branches, there were no differences in the proportions of NOS+ and VIP+ fibers between nerve bundles in each of the tissue strips. Thus, target-dependent sorting of nerve fibers was not apparent in the HGN at the level of the sacral promontory or in the PSN near the third sacral nerve root. The NOS+ and/or VIP+ fibers in the HGN were most likely ascending postganglionic fibers to the colon, while those in the PSN root may be preganglionic fibers from Onuf's nucleus.

  19. Central changes in primary afferent fibers following peripheral nerve lesions

    Microsoft Academic Search

    R. E Coggeshall; H. A Lekan; T. P Doubell; A Allchorne; C. J Woolf

    1997-01-01

    Cutting or crushing rat sciatic nerve does not significantly reduce the number of central myelinated sensory axons in the dorsal roots entering the fourth and fifth lumbar segments even over very extended periods of time. Unmyelinated axons were reduced by ?50%, but only long after sciatic nerve lesions (four to eight months), and reinnervation of the peripheral target did not

  20. MODIFICATION OF A RAPIDLY TRANSPORTED PROTEIN IN REGENERATING NERVE1

    Microsoft Academic Search

    BRUCE TEDESCHI; DAVID L. WILSON

    From 1 to 28 days after frog sciatic nerve damage, dorsal root ganglia were incubated with (35S) methionine, and the labeled, rapidly transported proteins at various points along the nerve were analyzed on two-dimensional gels. The results show a dramatic increase in the labeling of a protein, which we have designated as A25, only after the arrival of the rapidly

  1. Femoral nerve dysfunction

    MedlinePLUS

    Neuropathy - femoral nerve; Femoral neuropathy ... Felice, KJ. Focal neuropathies of the femoral, obturator, lateral femoral cutaneous and other nerves of the thigh and pelvis. In: Bromberg MB, Smith ...

  2. Early Degenerative Nerve Alterations in Feline Resorbing Deciduous Incisors as Observed by Electron Microscopy

    Microsoft Academic Search

    Ulf Karlsson; David Johnsen; Anne Marie Herman

    1974-01-01

    Electron microscopy was used to assess degenerative nerve alterations in resorbing deciduous incisors of the cat. Intradental nerve structural changes are described when minimal signs of root resorption are present. Intradental nerves in resorbing deciduous incisors are compared with those of fully developed deciduous incisors.

  3. Continuous conduction in demyelinated mammalian nerve fibres

    Microsoft Academic Search

    H. Bostock; T. A. Sears

    1976-01-01

    MYELINATED nerve fibres conduct in a saltatory fashion, with sites of inward membrane current restricted to the nodes of Ranvier1. Loss of myelin causes long delays in the inter nodal conduction time, extreme refractoriness and conduction block2. In the large rat ventral root fibres studied the slowed conduction always remained saltatory, with discrete sites of inward current, but the limited

  4. Optogenetic control of nerve growth

    PubMed Central

    Park, Seongjun; Koppes, Ryan A.; Froriep, Ulrich P.; Jia, Xiaoting; Achyuta, Anil Kumar H.; McLaughlin, Bryan L.; Anikeeva, Polina

    2015-01-01

    Due to the limited regenerative ability of neural tissue, a diverse set of biochemical and biophysical cues for increasing nerve growth has been investigated, including neurotrophic factors, topography, and electrical stimulation. In this report, we explore optogenetic control of neurite growth as a cell-specific alternative to electrical stimulation. By investigating a broad range of optical stimulation parameters on dorsal root ganglia (DRGs) expressing channelrhodopsin 2 (ChR2), we identified conditions that enhance neurite outgrowth by three-fold as compared to unstimulated or wild-type (WT) controls. Furthermore, optogenetic stimulation of ChR2 expressing DRGs induces directional outgrowth in WT DRGs co-cultured within a 10?mm vicinity of the optically sensitive ganglia. This observed enhancement and polarization of neurite growth was accompanied by an increased expression of neural growth and brain derived neurotrophic factors (NGF, BDNF). This work highlights the potential for implementing optogenetics to drive nerve growth in specific cell populations. PMID:25982506

  5. Utility of direct stimulation of roots in spinal surgery.

    PubMed

    Takeda, Masaaki; Yamaguchi, Satoshi; Morishige, Mizuki; Eguchi, Kuniki; Kurisu, Kaoru

    2011-01-01

    Prevention of postoperative neurological deficits is a major concern of spinal surgeons and has led to the introduction and current development of intraoperative neurophysiological monitoring. We have used motor evoked potentials and somatosensory evoked potentials as routine monitoring techniques and, in some cases, added optional methods such as direct stimulation of nerve roots and spinal evoked potentials. We report our experience of direct nerve root stimulation as an optional monitoring method during spinal surgeries in 7 patients with lesions affecting the proximal nerve roots aged from 1 day to 78 years (mean 23.5 years). Four patients had anomalous lesions, two had spinal nerve root schwannomas, and one had a far-lateral lumbar disc herniation. Direct stimulation was used for detection of motor nerve roots in the anomalous lesions and schwannomas, and to distinguish the nerve root from the paraspinal soft tissues in the case of a far-lateral herniated disc at the L5-S1 level. Although some patients had slight transient neurological symptoms such as motor weakness and sensory disturbance, none developed severe permanent neurological impairment. Direct stimulation allows detection of the motor nerve during spinal surgery in real time. Our limited experience suggests that the direct stimulation technique could reduce the risk of motor or vesicorectal disturbance after surgery of lesions affecting or involving the spinal nerve roots. PMID:21613760

  6. The vestibulocochlear nerve (VIII).

    PubMed

    Benoudiba, F; Toulgoat, F; Sarrazin, J-L

    2013-10-01

    The vestibulocochlear nerve (8th cranial nerve) is a sensory nerve. It is made up of two nerves, the cochlear, which transmits sound and the vestibular which controls balance. It is an intracranial nerve which runs from the sensory receptors in the internal ear to the brain stem nuclei and finally to the auditory areas: the post-central gyrus and superior temporal auditory cortex. The most common lesions responsible for damage to VIII are vestibular Schwannomas. This report reviews the anatomy and various investigations of the nerve. PMID:24095603

  7. Iatrogenic nerve injuries.

    PubMed

    Kretschmer, Thomas; Heinen, Christian W; Antoniadis, Gregor; Richter, Hans-Peter; König, Ralph W

    2009-01-01

    As long as humans have been medically treated, unfortunate cases of inadvertent injury to nerves afflicted by the therapist have occurred. Most microsurgically treated iatrogenic nerve injuries occur directly during an operation. Certain nerves are at a higher risk than others, and certain procedures and regions of the body are more prone to sustaining nerve injury. A high degree of insecurity regarding the proper measures to take can be observed among medical practitioners. A major limiting factor in successful treatment is delayed referral for evaluation and reconstructive surgery. This article on iatrogenic nerve injuries intends to focus on relevant aspects of management from a nerve surgeon's perspective. PMID:19064181

  8. A Mechanical Model of Neural Tissue Displacement During Lorentz Effect Imaging

    PubMed Central

    Roth, Bradley J.; Basser, Peter J.

    2009-01-01

    Song and co-workers recently proposed a method for MRI detection of biocurrents in nerves called “Lorentz Effect Imaging”. When exposed to a magnetic field, neural currents are subjected to a Lorentz force that moves the nerve. If the displacement is large enough, an artifact is predicted in the MR signal. In this paper, the displacement of a nerve of radius a in a surrounding tissue of radius b and shear modulus µ is analyzed. The nerve carries a current density J and lies in a magnetic field B. The solution to the resulting elasticity problem indicates that the nerve moves a distance BJ4?a2ln(ba). Using realistic parameters for a human median nerve in a 4 T field, this calculated displacement is 0.013 µm or less. The distribution of displacement is widespread throughout the tissue, and is not localized near the nerve. This displacement is orders of magnitude too small to be observed by conventional MRI methods. PMID:19097218

  9. Abducens nerve palsy after schwannoma resection.

    PubMed

    Bobbio, Antonio; Hamelin-Canny, Emelyne; Roche, Nicolas; Taillia, Herve; Alifano, Marco

    2015-02-01

    Tumors of the posterior mediastinum are mostly neurogenic and could involve the intervertebral foramen and the medullary canal. We describe the case of a patient who underwent surgery for a nerve sheet tumor originating at the level of the right second neural root. Resection was associated with an incidental dural tear and cerebrospinal fluid leak that was promptly repaired. One week after surgery, horizontal diplopia occurred. A palsy of the left abducens nerve secondary to intracranial hypotension was diagnosed. We present the pathogenic cascade leading to this ocular complication after posterior mediastinal surgery. The surgical techniques to prevent this complication are discussed. PMID:25639411

  10. Ulnar nerve damage (image)

    MedlinePLUS

    ... arm. The nerve is commonly injured at the elbow because of elbow fracture or dislocation. The ulnar nerve is near ... surface of the body where it crosses the elbow, so prolonged pressure on the elbow or entrapment ...

  11. Engineering Peripheral Nerve Repair

    PubMed Central

    Marquardt, Laura; Sakiyama-Elbert, Shelly E.

    2013-01-01

    Current approaches for treating peripheral nerve injury have resulted in promising, yet insufficient functional recovery compared to the clinical standard of care, autologous nerve grafts. In order to design a construct that can match the regenerative potential of the autograft, all facets of nerve tissue must be incorporated in a combinatorial therapy. Engineered biomaterial scaffolds in the future will have to promote enhanced regeneration and appropriate reinnervation by targeting the highly sensitive response of regenerating nerves to their surrounding microenvironment. PMID:23790730

  12. Cranial Nerves Model

    NSDL National Science Digital Library

    Juliann Garza (University of Texas-Pan American Physician Assistant Studies)

    2010-08-16

    Lesson is designed to introduce students to cranial nerves through the use of an introductory lecture. Students will then create a three-dimensional model of the cranial nerves. An information sheet will accompany the model in order to help students learn crucial aspects of the cranial nerves.

  13. Optic Nerve Imaging

    MedlinePLUS

    ... machines can help monitor and detect loss of optic nerve fibers. The Heidelberg Retina Tomograph (HRT) is a special ... can directly measure the thickness of the nerve fiber layer and create a three dimensional representation of the optic nerve. Last reviewed on May 02, 2012 Was ...

  14. The utility of three-dimensional optical projection tomography in nerve injection injury imaging.

    PubMed

    Cvetko, E; ?apek, M; Damjanovska, M; Reina, M A; Eržen, I; Stopar-Pintari?, T

    2015-08-01

    The examination of nerve microarchitecture has hitherto been limited solely to two-dimensional imaging techniques. The objective of this study was to evaluate the ability of optical projection tomography to discern the nerve microarchitecture and injection injury in three dimensions. Five piglets were studied, whose median and lingual nerves were unilaterally injected post mortem with preset volumes of local anaesthetic, excised and subsequently made transparent with benzyl alcohol benzyl benzoate. Images were captured in three dimensions. The same contralateral nerves were used as controls. Using optical projection tomography, we observed differences between the internal organisation of the median and the lingual nerves, which potentially explain the variations in their susceptibility to injury. This was demonstrated in three dimensions as a disruption to the fascicles in the lingual nerve, and their displacement in the median nerve. This new technology offers potential for studying nerve microarchitecture topography and its tolerance to injection injury. PMID:25827062

  15. Chromo-fluorogenic BODIPY-complexes for selective detection of V-type nerve agent surrogates.

    PubMed

    Barba-Bon, Andrea; Costero, Ana María; Gil, Salvador; Sancenón, Félix; Martínez-Máñez, Ramón

    2014-11-11

    Two new Eu(3+) and Au(3+) BODIPY-complexes capable of chromo-fluorogenically detecting micromolar concentrations of V-type nerve agent surrogates by a simple displacement assay are described. PMID:25233370

  16. Root systems

    NSDL National Science Digital Library

    N/A N/A (U.S. Government; )

    2004-10-30

    One purpose that roots serve is that of anchoring the plant in the ground. Roots also take up water and nutrients for the plant. Plants all have different root system types to fit their individual needs and locations.

  17. Nerve Conduction Velocity of Small Components in Human Sensory Nerves

    Microsoft Academic Search

    W. Tackmann; R. Minkenberg

    1977-01-01

    Slow conducted components of sensory nerve action potentials were investigated in median and in sural nerves of controls and in patients with peripheral nerve diseases. In the normal group the slow components showed no relation to age which is in contrast to the maximum velocity. In both the median nerve and sural nerve of about 20% of the patients with

  18. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F. (Albuquerque, NM); Dubois, Robert R. (Albuquerque, NM); Strother, Jerry D. (Edgewood, NM)

    2000-02-22

    A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

  19. Peripheral nerve regeneration and neurotrophic factors

    PubMed Central

    TERENGHI, GIORGIO

    1999-01-01

    The role of neurotrophic factors in the maintenance and survival of peripheral neuronal cells has been the subject of numerous studies. Administration of exogenous neurotrophic factors after nerve injury has been shown to mimic the effect of target organ-derived trophic factors on neuronal cells. After axotomy and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF show a well defined and selective beneficial effect on the survival and phenotypic expression of primary sensory neurons in dorsal root ganglia and of motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and LIF also exert a variety of actions on neuronal cells, which appear to overlap and complement those of the neurotrophins. In addition, there is an indirect contribution of GGF to nerve regeneration. GGF is produced by neurons and stimulates proliferation of Schwann cells, underlining the close interaction between neuronal and glial cells during peripheral nerve regeneration. Different possibilities have been investigated for the delivery of growth factors to the injured neurons, in search of a suitable system for clinical applications. The studies reviewed in this article show the therapeutic potential of neurotrophic factors for the treatment of peripheral nerve injury and for neuropathies. PMID:10227662

  20. Sensory nerves and pancreatitis

    PubMed Central

    Li, Qingfu

    2014-01-01

    Sensory nerves are a kind of nerve that conduct afferent impulses from the periphery receptors to the central nervous system (CNS) and are able to release neuromediators from the activated peripheral endings. Sensory nerves are particularly important for microcirculatory response, and stimulation of pancreatic sensory nerves releases a variety of neuropeptides such as substance P (SP), calcitonin gene-related peptide (CGRP), etc., leading to neurogenic inflammation characterized as the local vasodilatation and plasma extravasation. Deactivation of sensory nerves often leads to the disturbances of pancreatic microcirculation. Pancreatitis is a common digestive disease that can lead to severe complications and even death if it goes untreated. Experimental studies in animals and tissue analysis in patients with pancreatitis have shown significant changes in sensory nerves supplying the pancreatic gland. Thus making clear the whole mechanism of pancreatitis is essential to treat and cure it. Sensory nerves may have a close correlation with the development of pancreatitis, and knowing more about the role of sensory nerve in pancreatitis is important for the treatment for pancreatitis. This review is aimed to summarize the relationship between sensory nerves and pancreatitis. PMID:25493260

  1. Distal median nerve dysfunction

    MedlinePLUS

    ... type of distal median nerve dysfunction is carpal tunnel syndrome . ... repetitive movements increase the chance of developing carpal tunnel entrapment. Conditions that affect connective tissue or cause ...

  2. Joint estimation of real squeezing and displacement

    E-print Network

    G. Chiribella; G. M. D'Ariano; M. F. Sacchi

    2006-01-18

    We study the problem of joint estimation of real squeezing and amplitude of the radiation field, deriving the measurement that maximizes the probability density of detecting the true value of the unknown parameters. More generally, we provide a solution for the problem of estimating the unknown unitary action of a nonunimodular group in the maximum likelihood approach. Remarkably, in this case the optimal measurements do not coincide with the so called square-root measurements. In the case of squeezing and displacement we analyze in detail the sensitivity of estimation for coherent states and displaced squeezed states, deriving the asymptotic relation between the uncertainties in the joint estimation and the corresponding uncertainties in the optimal separate measurements of squeezing and displacement. A two-mode setup is also analyzed, showing how entanglement between optical modes can be used to approximate perfect estimation.

  3. Communication between radial nerve and medial cutaneous nerve of forearm

    PubMed Central

    Marathe, RR; Mankar, SR; Joshi, M; Sontakke, YA

    2010-01-01

    Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm. PMID:21799623

  4. Propagation Speed in Myelinated Nerve

    PubMed Central

    Hardy, W. L.

    1973-01-01

    The Hodgkin-Huxley (H.H.) equations modified by Dodge for Rana pipiens myelinated nerve have been solved to determine how well the theory predicts the effects of changes of temperature and [Na+]0 on propagation. Conduction speed ? was found to have an approximately exponential dependence on temperature as was found experimentally, but the theoretical temperature coefficient (Q10) was low; 1.5 compared with the experimental finding of 2.95. ? was found to be a linear function of log ([Na+]0) in contrast to the experimental finding of a square root dependence on [Na+]0. ? is 50% greater at one-fourth normal [Na+]0 than the theory predicts. The difference between the theoretical ?([Na+]0) and the experimental ?([Na+]0) is probably due to an imprecisely known variation of parameters and not to a fundamental inadequacy of the theory. PMID:4542941

  5. Motor nerve transplantation.

    PubMed

    Gray, W P; Keohane, C; Kirwan, W O

    1997-10-01

    The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 microsec preoperatively, and 26 microsec at 2 months, 29.5 microsec at 4 months, and 14 microsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle. PMID:9322851

  6. Immunity to Nerve Growth Factor Prevents Afferent Plasticity Following Urinary Bladder Hypertrophy

    Microsoft Academic Search

    William D. Steers; Douglas J. Creedon; Jeremy B. Tuttle

    1996-01-01

    PurposeThe goal of this investigation was to examine the effect of immunity to nerve growth factor (NGF) on alterations in sensory nerves from the urinary bladder in the dorsal root ganglia (DRG) and their projections to the L6\\/S1 spinal cord following urethral obstruction in the rat.

  7. Stimulation of the greater occipital nerve induces increased central excitability of dural afferent input

    Microsoft Academic Search

    Thorsten Bartsch; Peter J. Goadsby

    2002-01-01

    Summary Patients with primary headaches often report pain that involves not only the front of the head, innervated by the first (ophthalmic) division of the trigeminal nerve, but also the back of the head, innervated by the greater occipital nerve (GON) that is a branch of the C2 spinal root. The aim of this work was to study the physiology

  8. Internal Displacement Monitoring Centre

    NSDL National Science Digital Library

    The Internal Displacement Monitoring Centre (IDMC) was established twelve years ago in the hope that they would "raise awareness of the plight of internally displaced people (IDP), point to gaps in national and international responses and promote solutions reflecting international standards and best practices." The Centre also keeps a database of 50 countries in which people have been displaced within their own country due to conflicts or human rights violations. To get a sense of where displaced persons are and how many countries have IDPs, visitors can click on the small world map on the far right hand side of the homepage. Scrolling over the map will reveal the number of displaced people by continent. Visitors interested in learning about an individual country can click on the continent, then click on one of the countries for an "Internal Displacement Profile", "Country Statistics", and an "Overview". The Resources tab, at the top of any page, includes "IDMC Publications", "Picture Galleries" of internally displaced people in India, Cyprus, and the West Bank, to name a few, and "IDP Maps" which has dozens of maps of from 2001 to 2009.

  9. In Vivo Contrast-Enhanced MR Imaging of Direct Infusion into Rat Peripheral Nerves

    PubMed Central

    Chen, Xiaoming; Astary, Garrett W.; Mareci, Thomas H.; Sarntinoranont, Malisa

    2011-01-01

    Direct infusion, or convection-enhanced delivery (CED), into peripheral nerves may provide a method for delivering substances to the intrathecal space or specific fiber bundles entering the spinal cord. To better understand this potential delivery technique, we have characterized the extracellular transport of macromolecular agents from peripheral nerves to the spinal cord in magnetic resonance (MR) imaging studies. High-resolution dynamic contrast-enhanced MR imaging at 11.1 T was used to monitor and characterize in vivo the extracellular transport dynamics of Gd-DTPA-albumin tracer during CED into rat sciatic nerves. Extracellular tracers followed peripheral nerves towards the spinal cord and at vertebral levels L4 and L5 appeared to enter the cerebrospinal fluid and nerve roots. Uptake directly into spinal cord tissues (white and gray matter) appeared to be limited. Spatial distribution patterns within spinal cord regions depended on CED factors, including cannula placement, and underlying tissue structures including peripheral nerve branching and membrane structures at nerve root entry. The applied MR techniques allowed for visualization and quantification of tracer spread and distribution within the rat spinal cord region. The results show that CED into peripheral nerves provides an alternative route for delivering therapeutics to nerve roots and the intrathecal space surrounding the spinal cord. PMID:21809145

  10. On the maxillary nerve.

    PubMed

    Higashiyama, Hiroki; Kuratani, Shigeru

    2014-01-01

    The trigeminal, the fifth cranial nerve of vertebrates, represents the rostralmost component of the nerves assigned to pharyngeal arches. It consists of the ophthalmic and maxillomandibular nerves, and in jawed vertebrates, the latter is further divided into two major branches dorsoventrally. Of these, the dorsal one is called the maxillary nerve because it predominantly innervates the upper jaw, as seen in the human anatomy. However, developmentally, the upper jaw is derived not only from the dorsal part of the mandibular arch, but also from the premandibular primordium: the medial nasal prominence rostral to the mandibular arch domain. The latter component forms the premaxillary region of the upper jaw in mammals. Thus, there is an apparent discrepancy between the morphological trigeminal innervation pattern and the developmental derivation of the gnathostome upper jaw. To reconcile this, we compared the embryonic developmental patterns of the trigeminal nerve in a variety of gnathostome species. With the exception of the diapsid species studied, we found that the maxillary nerve issues a branch (nasopalatine nerve in human) that innervates the medial nasal prominence derivatives. Because the trigeminal nerve in cyclostomes also possesses a similar branch, we conclude that the vertebrate maxillomandibular nerve primarily has had a premandibular branch as its dorsal element. The presence of this branch would thus represent the plesiomorphic condition for the gnathostomes, implying its secondary loss within some lineages. The branch for the maxillary process, more appropriately called the palatoquadrate component of the maxillary nerve (V(2)), represents the apomorphic gnathostome trait that has evolved in association with the acquisition of an upper jaw. PMID:24151219

  11. Nerve fiber planimetry in acute and chronic nerve lesions and in nerve lesions in continuity.

    PubMed

    Guelinckx, P J; Boeckx, W D; Dom, R; Gruwez, J A

    1985-10-01

    The level of resection of damaged nerve tissue in acute and chronic nerve lesions was determined on the basis of the vascular structure, the consistency of the nerve during palpation, the amount of interfascicular connective tissue, and the mushroom formation of the fascicles. Intraoperative electrophysiologic recordings were performed on the cut nerve ends to determine the function of the axons. Postoperative planimetric analyses of cross sections made through the resected nerve stumps were performed to measure axonal and endoneural tube diameters and to correlate these results with the clinical criteria used through the operating microscope. Axons in the proximal nerve ends of acute and chronic nerve lesions displayed a similar mean diameter. Endoneural tubes in chronic nerve lesions shrunk significantly as nerve repair was delayed. In several nerve lesions in continuity, axons remained present across the injured site despite absence of electrical conduction. When comparing the results of axonal or endoneural tube diameters of chronic nerve lesions to the results of other studies or acute nerve lesions, we demonstrated that careful examination through the operating microscope provided valid information about the proper management and resection level of chronic nerve lesions. Electrophysiologic evaluation aided the surgical management but was not useful for the resection of the distal damaged nerve segment. The presence of an evoked potential in the proximal nerve ends guaranteed a nearly normal nerve fiber diameter distribution, while the absence of such a potential in the distal nerve ends indicated an abnormal, absent, or disturbed endoneural tube diameter histogram. PMID:4034768

  12. Suprascapular nerve entrapment.

    PubMed

    Corò, L; Azuelos, A; Alexandre, A

    2005-01-01

    It is important to be aware of neuropathy involving the suprascapular nerve. While direct trauma to the suprascapular nerve is the usual cause (direct blow to the base of the neck or posterior shoulder, shoulder dislocation or fracture), the problem may result from overuse injuries (such as repetitive tennis serving or spiking of a volley ball), excessive horizontal adduction, weight lifting, backpacking or no apparent reason. These last three years we have operated 8 cases of suprascapular nerve neurolysis at the level of suprascapular incision, and section of the transverse scapular ligament through the back supraspinal approach. PMID:15830964

  13. Intracranial facial nerve reconstruction.

    PubMed

    Yammine, F G; Dufour, J J; Mohr, G

    1999-06-01

    Surgery for tumours of the cerebellopontine angle (CPA) or the internal auditory canal (IAC) is sometimes complicated by the severing of the seventh nerve. Many procedures are available for facial reanimation. Among these, primary intracranial VII-VII reanastomosis is considered as the method of choice. This series reviews all the cases of primary intracranial facial nerve reconstruction that we have performed either directly or with the use of a nerve graft interposition. Functional results are analyzed according to the House-Brackmann grading scale. The advantages and benefits of this technique are discussed as compared with other methods of facial reanimation, namely, the hypoglossal-facial anastomosis. PMID:10410348

  14. Nerve growth factor decreases in sympathetic and sensory nerves of rats with chronic heart failure.

    PubMed

    Xing, Jihong; Lu, Jian; Li, Jianhua

    2014-08-01

    Nerve growth factor (NGF) plays a critical role in the maintenance and survival of both sympathetic and sensory nerves. Also, NGF can regulate receptor expression and neuronal activity in the sympathetic and sensory neurons. Abnormalities in NGF regulation are observed in patients and animals with heart failure (HF). Nevertheless, the effects of chronic HF on the levels of NGF within the sympathetic and sensory nerves are not known. Thus, the ELISA method was used to assess the levels of NGF in the stellate ganglion (SG) and dorsal root ganglion (DRG) neurons of control rats and rats with chronic HF induced by myocardial infarction. Our data show for the first time that the levels of NGF were significantly decreased (P < 0.05) in the SG and DRG neurons 6-20 weeks after ligation of the coronary artery. In addition, a close relation was observed between the NGF levels and the left ventricular function. In conclusion, chronic HF impairs the expression of NGF in the sympathetic and sensory nerves. Given that sensory afferent nerves are engaged in the sympathetic nervous responses to somatic stimulation (i.e. muscle activity during exercise) via a reflex mechanism, our data indicate that NGF is likely responsible for the development of muscle reflex-mediated abnormal sympathetic responsiveness observed in chronic HF. PMID:24913185

  15. Nerve Growth Factor Decreases in Sympathetic and Sensory Nerves of Rats with Chronic Heart Failure

    PubMed Central

    Lu, Jian

    2014-01-01

    Nerve growth factor (NGF) plays a critical role in the maintenance and survival of both sympathetic and sensory nerves. Also, NGF can regulate receptor expression and neuronal activity in the sympathetic and sensory neurons. Abnormalities in NGF regulation are observed in patients and animals with heart failure (HF). Nevertheless, the effects of chronic HF on the levels of NGF within the sympathetic and sensory nerves are not known. Thus, the ELISA method was used to assess the levels of NGF in the stellate ganglion (SG) and dorsal root ganglion (DRG) neurons of control rats and rats with chronic HF induced by myocardial infarction. Our data show for the first time that the levels of NGF were significantly decreased (P < 0.05) in the SG and DRG neurons 6–20 weeks after ligation of the coronary artery. In addition, a close relation was observed between the NGF levels and the left ventricular function. In conclusion, chronic HF impairs the expression of NGF in the sympathetic and sensory nerves. Given that sensory afferent nerves are engaged in the sympathetic nervous responses to somatic stimulation (i.e. muscle activity during exercise) via a reflex mechanism, our data indicate that NGF is likely responsible for the development of muscle reflex-mediated abnormal sympathetic responsiveness observed in chronic HF. PMID:24913185

  16. A novel chondroitin sulfate hydrogel for nerve repair

    NASA Astrophysics Data System (ADS)

    Conovaloff, Aaron William

    Brachial plexus injuries affect numerous patients every year, with very debilitating results. The majority of these cases are very severe, and involve damage to the nerve roots. To date, repair strategies for these injuries address only gross tissue damage, but do not supply cells with adequate regeneration signals. As a result, functional recovery is often severely lacking. Therefore, a chondroitin sulfate hydrogel that delivers neurotrophic signals to damaged neurons is proposed as a scaffold to support nerve root regeneration. Capillary electrophoresis studies revealed that chondroitin sulfate can physically bind with a variety of neurotrophic factors, and cultures of chick dorsal root ganglia demonstrated robust neurite outgrowth in chondroitin sulfate hydrogels. Outgrowth in chondroitin sulfate gels was greater than that observed in control gels of hyaluronic acid. Furthermore, the chondroitin sulfate hydrogel's binding activity with nerve growth factor could be enhanced by incorporation of a synthetic bioactive peptide, as revealed by fluorescence recovery after photobleaching. This enhanced binding was observed only in chondroitin sulfate gels, and not in hyaluronic acid control gels. This enhanced binding activity resulted in enhanced dorsal root ganglion neurite outgrowth in chondroitin sulfate gels. Finally, the growth of regenerating dorsal root ganglia in these gels was imaged using label-free coherent anti-Stokes scattering microscopy. This technique generated detailed, high-quality images of live dorsal root ganglion neurites, which were comparable to fixed, F-actin-stained samples. Taken together, these results demonstrate the viability of this chondroitin sulfate hydrogel to serve as an effective implantable scaffold to aid in nerve root regeneration.

  17. The "vagal ansa": a source of complication in vagus nerve stimulation.

    PubMed

    Gopalakrishnan, Chittur Viswanathan; Kestle, John R W; Connolly, Mary B

    2015-05-01

    A 16-year-old boy underwent vagus nerve stimulation for treatment-resistant multifocal epilepsy. During intraoperative system diagnostics, vigorous contraction of the ipsilateral sternomastoid muscle was observed. On re-exploration, a thin nerve fiber passing from the vagus to the sternomastoid was found hooked up in the upper electrode. Detailed inspection revealed an abnormal course of the superior root of the ansa cervicalis, which descended down as a single nerve trunk with the vagus and separated to join the inferior root. The authors discuss the variation in the course of the ansa cervicalis and how this could be a reason for postoperative neck muscle contractions. PMID:25700120

  18. Ulnar nerve dysfunction

    MedlinePLUS

    ... surface of the body where it crosses the elbow. The damage destroys the nerve covering ( myelin sheath) ... be caused by: Long-term pressure on the elbow An elbow fracture or dislocation Temporary pain and ...

  19. Diabetic Nerve Problems

    MedlinePLUS

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  20. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  1. Vagus Nerve Stimulation.

    PubMed

    Howland, Robert H

    2014-06-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  2. Sural nerve defects after nerve biopsy or nerve transfer as a sensory regeneration model for peripheral nerve conduit implantation.

    PubMed

    Radtke, C; Kocsis, J D; Reimers, K; Allmeling, C; Vogt, P M

    2013-09-01

    Nerve repair after injury can be effectively accomplished by direct suture approximation of the proximal and distal segments. This is more successful if coadaptation can be achieved without tension. Currently, the gold standard repair of larger deficits is the transplantation of an autologous sensory sural nerve graft. However, a significant disadvantage of this technique is the inevitable donor morbidity (sensory loss, neuroma and scar formation) after harvesting of the sural nerve. Moreover, limitation of autologous donor nerve length and fixed diameter of the available sural nerve are major drawbacks of current autograft treatment. Another approach that was introduced for nerve repair is the implantation of alloplastic nerve tubes made of, for example, poly-L-lactide. In these, nerve stumps of the transected nerves are surgically bridged using the biosynthetic conduit. A number of experimental studies, primarily in rodents, indicate axonal regeneration and remyelination after implantation of various conduits. However, only limited clinical studies with conduit implantation have been performed in acute peripheral nerve injuries particularly on digital nerves. Clinical transfer of animal studies, which can be carefully calibrated for site and extent of injury, to humans is difficult to interpret due to the intrinsic variability in human nerve injuries. This prevents effective quantification of improvement and induces bias in the study. Therefore, standardization of lesion/repair in human studies is warranted. Here we propose to use sural nerve defects, induced due to nerve graft harvesting or from diagnostic nerve biopsies as a model site to enable standardization of nerve conduit implantation. This would help better with the characterization of the implants and its effectiveness in axonal regeneration and remyelination. Nerve regeneration can be assessed, for example, by recovery of sensation, measured non-invasively by threshold to von Frey filaments and cold allodynia. Moreover, the implantation of nerve conduits may not only serve as a model to examine nerve repair, but it could also prevent neuroma formation, which is a major morbidity of sural nerve extraction. PMID:23867139

  3. Optic nerve aspergillosis.

    PubMed

    Yuan, Lisi; Prayson, Richard A

    2015-07-01

    We report a 55-year-old woman with optic nerve Aspergillosis. Aspergillus is an ubiquitous airborne saprophytic fungus. Inhaled Aspergillus conidia are normally eliminated in the immunocompetent host by innate immune mechanisms; however, in immunosuppressed patients, they can cause disease. The woman had a past medical history of hypertension and migraines. She presented 1year prior to death with a new onset headache behind the left eye and later developed blurred vision and scotoma. A left temporal artery biopsy was negative for giant cell arteritis. One month prior to the current admission, she had an MRI showing optic nerve thickening with no other findings. Because of the visual loss and a positive antinuclear antibody test, she was given a trial of high dose steroids and while it significantly improved her headache, her vision did not improve. At autopsy, the left optic nerve at the level of the cavernous sinus and extending into the optic chiasm was enlarged in diameter and there was a 1.3cm firm nodule surrounding the left optic nerve. Histologically, an abscess surrounded and involved the left optic nerve. Acute angle branching, angioinvasive fungal hyphae were identified on Grocott's methenamine silver stained sections, consistent with Aspergillus spp. No gross or microscopic evidence of systemic vasculitis or infection was identified in the body. The literature on optic nerve Aspergillosis is reviewed. PMID:25861888

  4. Ultrasound in Dual Nerve Impairment after Proximal Radial Nerve Lesion

    PubMed Central

    Lämmer, Alexandra B; Schwab, Stefan; Schramm, Axel

    2015-01-01

    Introduction Sonography in classical nerve entrapment syndromes is an established and validated method. In contrast, few publications highlight lesions of the radial nerve, particularly of the posterior interosseus nerve (PIN). Method Five patients with a radial nerve lesion were investigated by electromyography, nerve conduction velocity and ultrasound. Further normative values of 26 healthy subjects were evaluated. Results Four patients presented a clinical and electrophysiological proximal axonal radial nerve lesion and one patient showed a typical posterior interosseous nerve syndrome (PINS). The patient with PINS presented an enlargement of the PIN anterior to the supinator muscle. However four patients with proximal lesions showed an unexpected significant enlargement of the PIN within the supinator muscle. Conclusion High-resolution sonography is a feasible method to demonstrate the radial nerve including its distal branches. At least in axonal radial nerve lesions, sonography might reveal abnormalities far distant from a primary proximal lesion site clearly distinct from the appearance in classical PINS. PMID:25992766

  5. Metastatic renal cell carcinoma mimicking a schwannoma in a dorsal root ganglion: case report.

    PubMed

    Wasserman, Jason K; Tsai, Eve C; Glikstein, Rafael; Mai, Kien T; Jansen, Gerard H

    2015-03-01

    Peripheral nerve tumors are soft-tissue tumors that can occur in any nerve throughout the body. The majority of peripheral nerve tumors arise from elements of the nerve sheath with the two most common being neurofibromas and schwannomas. More than 90% of all peripheral nerve tumors are benign. When there is peripheral nerve involvement in metastatic carcinoma, it is often via contiguous spread from the primary mass; hematogenous seeding to a peripheral nerve is seldom seen. In this report the authors describe the even rarer case of metastatic renal cell carcinoma mimicking a schwannoma in a dorsal root ganglion. Cases from the literature show the rarity of this finding and its late clinical appearance. Given that survival in patients with metastatic carcinoma continues to increase, dorsal root ganglion metastasis may become more common over time. PMID:25555049

  6. Peripheral Nerve Repair in Rats Using Composite Hydrogel-Filled Aligned Nanofiber Conduits with Incorporated Nerve Growth Factor

    PubMed Central

    Jin, Jenny; Limburg, Sonja; Joshi, Sunil K.; Landman, Rebeccah; Park, Michelle; Zhang, Qia; Kim, Hubert T.

    2013-01-01

    Repair of peripheral nerve defects with current synthetic, tubular nerve conduits generally shows inferior recovery when compared with using nerve autografts, the current gold standard. We tested the ability of composite collagen and hyaluronan hydrogels, with and without the nerve growth factor (NGF), to stimulate neurite extension on a promising aligned, nanofiber poly-L-lactide-co-caprolactone (PLCL) scaffold. In vitro, the hydrogels significantly increased neurite extension from dorsal root ganglia explants. Consistent with these results, the addition of hydrogels as luminal fillers within aligned, nanofiber tubular PLCL conduits led to improved sensory function compared to autograft repair in a critical-size defect in the sciatic nerve in a rat model. Sensory recovery was assessed 3 and 12 weeks after repair using a withdrawal assay from thermal stimulation. The addition of hydrogel did not enhance recovery of motor function in the rat model. The NGF led to dose-dependent improvements in neurite out-growth in vitro, but did not have a significant effect in vivo. In summary, composite collagen/hyaluronan hydrogels enhanced sensory neurite outgrowth in vitro and sensory recovery in vivo. The use of such hydrogels as luminal fillers for tubular nerve conduits may therefore be useful in assisting restoration of protective sensation following peripheral nerve injury. PMID:23659607

  7. Sensitivity of the "Root Bundle Model" to root mechanical properties and root distribution: Implication for shallow landslide stability.

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Giadrossich, Filippo; Cohen, Denis

    2015-04-01

    Root reinforcement is recognized as an important factor for shallow landslides stability. Due to the complexity of root reinforcement mechanisms and the heterogeneity of the root-soil system, the estimation of parameters used in root reinforcement models is difficult, time consuming, and often highly uncertain. For practical applications, it is necessary to focus on the estimation of the most relevant parameters. The objective of the present contribution is to review the state of the art in the development of root reinforcement models and to discuss the sensitivity of the "Root Bundle Model" (RBM) when considering the variability of root mechanical properties and the heterogeneity of root distributions. The RBM is a strain-step loading fiber bundle model extended to include the mechanical and geometrical properties of roots. The model allows the calculation of the force-displacement behavior of a root bundle. In view of new results of field pullout tests performed on coarse roots of spruce (Picea abies) and considering a consistent dataset of root distribution of alpine tree species, we quantify the sensitivity of the RBM and the uncertainty associated with the most important input parameters. Preliminary results show that the extrapolation of force-diameter values from incomplete datasets (i.e., when only small roots are tested and values for coarse roots are extrapolated) may result in considerable errors. In particular, in the case of distributions with root diameters larger than 5 mm, root reinforcement tends to be dominated by coarse roots and their mechanical properties need to be quantified. In addition to the results of the model sensitivity, we present a possible best-practice method for the quantification of root reinforcement in view of its application to slope stability calculations and implementations in numerical models.

  8. Immediate Anti-tumor Necrosis Factor-? (Etanercept) Therapy Enhances Axonal Regeneration After Sciatic Nerve Crush

    PubMed Central

    Kato, Kinshi; Liu, Huaqing; Kikuchi, Shin-ichi; Myers, Robert R.; Shubayev, Veronica I.

    2015-01-01

    Peripheral nerve regeneration begins immediately after injury. Understanding the mechanisms by which early modulators of axonal degeneration regulate neurite outgrowth may affect the development of new strategies to promote nerve repair. Tumor necrosis factor-? (TNF-?) plays a crucial role in the initiation of degenerative cascades after peripheral nerve injury. Here we demonstrate using real-time Taqman quantitative RT-PCR that, during the time course (days 1–60) of sciatic nerve crush, TNF-? mRNA expression is induced at 1 day and returned to baseline at 5 days after injury in nerve and the corresponding dorsal root ganglia (DRG). Immediate therapy with the TNF-? antagonist etanercept (fusion protein of TNFRII and human IgG), administered systemically (i.p.) and locally (epineurially) after nerve crush injury, enhanced the rate of axonal regeneration, as determined by nerve pinch test and increased number of characteristic clusters of regenerating nerve fibers distal to nerve crush segments. These fibers were immunoreactive for growth associated protein-43 (GAP-43) and etanercept, detected by anti-human IgG immunofluorescence. Increased GAP-43 expression was found in the injured nerve and in the corresponding DRG and ventral spinal cord after systemic etanercept compared with vehicle treatments. This study established that immediate therapy with TNF-? antagonist supports axonal regeneration after peripheral nerve injury. PMID:19746434

  9. Combined nerve transfers for repair of the upper brachial plexus injuries through a posterior approach.

    PubMed

    Lu, Jiuzhou; Xu, Jianguang; Xu, Wendong; Xu, Lei; Fang, Yousheng; Chen, Liang; Gu, Yudong

    2012-02-01

    The upper brachial plexus injury leads to paralysis of muscles innervated by C5 and C6 nerve roots. In this report, we present our experience on the use of the combined nerve transfers for reconstruction of the upper brachial plexus injury. Nine male patients with the upper brachial plexus injury were treated with combined nerve transfers. The time interval between injury and surgery ranged from 3 to 11 months (average, 7 months). The combined nerve transfers include fascicles of the ulnar nerve and/or the median nerve transfer to the biceps and/or the brachialis motor branch, and the spinal accessory nerve (SAN) to the suprascapular nerve (SSN) and triceps branches to the axillary nerve through a posterior approach. At an average of 33 months of follow-up, all patients recovered the full range of the elbow flexion. Six out of nine patients were able to perform the normal range of shoulder abduction with the strength degraded to M3 or M4. These results showed that the technique of the combined nerve transfers, specifically the SAN to the SSN and triceps branches to the axillary nerve through a posterior approach, may be a valuable alternative in the repair of the upper brachial plexus injury. Further evaluations of this technique are necessary. PMID:22002897

  10. Repair of sciatic nerve defects using tissue engineered nerves

    PubMed Central

    Zhang, Caishun; Lv, Gang

    2013-01-01

    In this study, we constructed tissue-engineered nerves with acellular nerve allografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cells of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tissue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acellular nerve allografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle; regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acellular nerve allografts. The hind limb motor function at the affected side was significantly improved, indicating that acellular nerve allografts combined with bone marrow mesenchymal stem cell bridging could promote functional recovery of rats with sciatic nerve defects. PMID:25206507

  11. Scaling Up Digital Circuit Computation with DNA Strand Displacement Cascades

    Microsoft Academic Search

    Lulu Qian; Erik Winfree

    2011-01-01

    To construct sophisticated biochemical circuits from scratch, one needs to understand how simple the building blocks can be and how robustly such circuits can scale up. Using a simple DNA reaction mechanism based on a reversible strand displacement process, we experimentally demonstrated several digital logic circuits, culminating in a four-bit square-root circuit that comprises 130 DNA strands. These multilayer circuits

  12. Spinal accessory nerve injury.

    PubMed

    Wiater, J M; Bigliani, L U

    1999-11-01

    Injury to the spinal accessory nerve can lead to dysfunction of the trapezius. The trapezius is a major scapular stabilizer and is composed of three functional components. It contributes to scapulothoracic rhythm by elevating, rotating, and retracting the scapula. The superficial course of the spinal accessory nerve in the posterior cervical triangle makes it susceptible to injury. Iatrogenic injury to the nerve after a surgical procedure is one of the most common causes of trapezius palsy. Dysfunction of the trapezius can be a painful and disabling condition. The shoulder droops as the scapula is translated laterally and rotated downward. Patients present with an asymmetric neckline, a drooping shoulder, winging of the scapula, and weakness of forward elevation. Evaluation should include a complete electrodiagnostic examination. If diagnosed within 1 year of the injury, microsurgical reconstruction of the nerve should be considered. Conservative treatment of chronic trapezius paralysis is appropriate for older patients who are sendentary. Active and healthy patients in whom 1 year of conservative treatment has failed are candidates for surgical reconstruction. Studies have shown the Eden-Lange procedure, in which the insertions of the levator scapulae, rhomboideus minor, and rhomboideus major muscles are transferred, relieves pain, corrects deformity, and improves function in patients with irreparable injury to the spinal accessory nerve. PMID:10613148

  13. Spontaneous action potential activity in isolated dorsal root ganglion neurons from rats with a painful neuropathy

    Microsoft Academic Search

    Robert E. Study; Michael G. Kral

    1996-01-01

    One of the physiological changes accompanying neuropathic pain from nerve injury is the spontaneous firing of primary afferent fibers. At least some of this activity is thought to arise from the dorsal root ganglion. We have investigated whether this activity is resident in the cell bodies of dorsal root ganglion neurons and if it is retained in vitro. Dorsal root

  14. Monkey median nerve repaired by nerve graft or collagen nerve guide tube.

    PubMed

    Archibald, S J; Shefner, J; Krarup, C; Madison, R D

    1995-05-01

    Nerve regeneration was followed in 15 median and 1 ulnar nerve of eight Macaca fascicularis monkeys by serial electrophysiological assessments over a period of three and a half years. Nerve gaps of 5 mm at the wrist were bridged by collagen-based nerve guides, nerve autografts, or direct suture repairs. Thenar muscle reinnervation occurred between 50 and 70 d for all groups, indicating axonal elongation rates of approximately 1 mm/d. The recovery rates of the compound muscle action potential (CMAP) and the compound sensory action potential (CSAP) amplitudes were significantly slower after direct suture repair compared to the other two procedures, although the final levels of recovery were all comparable. Similar results were achieved in one median and one ulnar nerve following nerve guide repair of a 15 mm nerve gap. The functional reinnervation of Pacinian corpuscles was detected in all cases following either nerve graft or nerve guide repair, with similar amplitudes and latencies of the tactile evoked CSAP for both types of repair. Histological analysis demonstrated a significant increase in the number of myelinated axons in the median nerve distal to the nerve lesions following both nerve graft and nerve guide repairs compared to proximal and normal controls, with significant reductions of fiber diameter and corresponding increases in g-ratio. The return of a bimodal frequency distribution of myelinated axon fiber diameter was confirmed by three-dimensional surface plots which illustrate the frequency distribution of the relationship between fiber diameter and g-ratio. These combined results demonstrate that nerve regeneration after repair of a 5 mm nerve gap with a collagen nerve guide in the nonhuman primate is similar to that after graft repair, and the final level of physiological recovery for both repair procedures is comparable to direct suture repair of the median nerve. PMID:7751969

  15. Biomarkers of organophosphorus nerve agent exposure: comparison of phosphylated butyrylcholinesterase and phosphylated albumin after oxime therapy

    Microsoft Academic Search

    Robert W. Read; James R. Riches; Jacqueline A. Stevens; Sarah J. Stubbs; Robin M. Black

    2010-01-01

    Organophosphorus nerve agents inhibit the activity of cholinesterases by phosphylation of the active site serine. In addition,\\u000a sarin, cyclosarin, soman and tabun have been shown to phosphylate a tyrosine residue in albumin. Therapies against nerve agent\\u000a poisoning include the use of oximes to reactivate inhibited cholinesterases by displacement of the phosphyl moiety and hence\\u000a detectable levels of adducts with cholinesterases

  16. Laparoscopic sacrocolpopexy: Demonstration of a nerve-sparing technique.

    PubMed

    Sarlos, Dimitri; Aigmueller, Thomas; Magg, Heimo; Schaer, Gabriel

    2015-06-01

    Laparoscopic sacrocolpopexy is a well-established technique to treat apical vaginal prolapse. De novo micturition disorders, pelvic pain, and defecation disorders have been reported and may be due to intraoperative compromise of the superior hypogastric plexus. The video demonstrates our technique for nerve-sparing laparoscopic sacrocolpopexy. The patient is a 62-year-old woman with symptomatic stage III posthysterectomy vaginal vault prolapse. Key steps of the procedure are opening the peritoneum at the level of the promontory, identification of the fibers of the superior hypogastric plexus, deep anterior and posterior dissection with attachment of the mesh to the vagina, displacement of the nerve fibers to the left side during suturing of the mesh to the longitudinal ligament, and complete peritonealization. This technique of the identification and protection of relevant nerve structures appears to be reproducible and can be considered by surgeons who perform laparoscopic sacrocolpopexy. PMID:25499262

  17. Lewis acid-assisted detection of nerve agents in water.

    PubMed

    Butala, Rahul R; Creasy, William R; Fry, Roderick A; McKee, Michael L; Atwood, David A

    2015-05-21

    The five-coordinate compound, Salen((t)Bu)Al(Ac), prepared in situ from Salen((t)Bu)AlBr and NH4Ac, forms Lewis acid-base adducts in aqueous solution with the G-type nerve agents, Sarin and Soman, and the VX hydrolysis product, ethylmethylphosphonate (EMPA). The resulting compounds, [Salen((t)Bu)Al(NA)](+)[Ac] (-) (with NA = Sarin, Soman, and EMPA) are sufficiently stable to be identified by ESI-MS. Molecular ion peaks were detected for every compound with little or no fragmentation. The distinctive MS signatures for the [Salen((t)Bu)Al(NA)](+) compounds provide a new technique for identifying nerve agents from aqueous solution. The energetics of the displacement of Ac(-) by the nerve agents to form [Salen((t)Bu)Al(NA)](+)[Ac](-) were determined computationally. PMID:25820753

  18. Overview of Optic Nerve Disorders

    MedlinePLUS

    ... each optic nerve splits, and half of its fibers cross over to the other side. Because of this anatomic arrangement, damage along the optic nerve pathway causes specific patterns of vision loss. ...

  19. Vascular mechanism of axonal degeneration in peripheral nerves in hemiplegic sides after cerebral hemorrhage: An experimental study

    Microsoft Academic Search

    Cemal Gundogdu; Memet Dumlu Aydin; Dilcan Kotan; Nazan Aydin; Ednan Bayram; H?z?r Ulvi; Recep Aygul

    2008-01-01

    BACKGROUND: Though retrograde neuronal death and vascular insufficiency have been well established in plegics following intracerebral hemorrhage, the effects of plegia on arterial nervorums of peripheral nerves have not been reported. In this study, the histopathological effects of the intracerebral hemorrhage on the dorsal root ganglions and sciatic nerves via affecting the arterial nervorums were investigated. METHODS: This study was

  20. Displacement and Velocity Ratios

    NSDL National Science Digital Library

    Bourassa, James

    This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses displacement and velocity ratios. Bourassa and Rosz begin by providing detailed definitions of both topics and then provide mathematical examples of each. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to the physical and mathematical concepts of displacement and velocity ratios. This could be a valuable learning resource in everything from a physics to a technical education classroom.

  1. Above Water: Buoyancy & Displacement

    NSDL National Science Digital Library

    New Jersey

    2006-01-01

    In an investigation called "Shape It!" learners craft tiny boats out of clay, set them afloat on water and then add weight loads to them, in order to explore: how objects stay afloat in water; what the relationship is among surface tension, buoyancy, density and displacement; and how shape, size, and type of material affect an object's ability to remain buoyant. The introductory text discusses how heavy steel ships can float on bodies of water like rivers, bays and oceans.

  2. Conduction studies of the normal sural nerve.

    PubMed

    Horowitz, S H; Krarup, C

    1992-03-01

    The sural nerve was studied orthodromically using the near-nerve technique in 273 normal subjects (155 females, 118 males) aged 5 to 90 years. The sensory action potential (SAP), evoked at the dorsum of the foot, was recorded at the lateral malleolus and midcalf, and at the midcalf when evoked at the lateral malleolus. In addition, the SAP was recorded at intermediate distal sites and at proximal sites at the popliteal fossa, the gluteal fold, and the S-1 root. The amplitude of the SAP recorded at midcalf was 32% higher in females than in males. This was probably due to volume-conduction properties, as differences between genders were less noticeable at more distal recording sites. The amplitude decreased steeply and exponentially with age. Conduction distance had a strong influence on the amplitude of the SAP, which decreased with increasing distance following a power relationship with an exponent of 1.4 to 1.7. This decrease was due to temporal dispersion with decreased summation and increased phase cancellation. The conduction velocity was slightly lower along the very distal course of the nerve than along more proximal segments. PMID:1557087

  3. Vagus Nerve Stimulation

    Microsoft Academic Search

    Arun Paul Amar; Michael L. Levy; Charles Y. Liu; Michael L. J. Apuzzo

    2008-01-01

    Vagus nerve stimulation (VNS) is a safe and reliable treatment adjunct for patients with medically intractable epilepsy. It is both a preventive and an abortive form of therapy, potentially effective against both partial and generalized seizures in adults and children. VNS also has a number of serendipitous effects on mood, memory, and attention and has been approved for the treatment

  4. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  5. Licorice Root

    MedlinePLUS

    ... sweet root, gan zao (Chinese licorice) Latin Name: Glycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice) licorice_foster.jpg © Steven Foster ... Sources Armanini D, Fiore C, Bielenberg J. Licorice ( Glycyrrhiza glabra ). In: Coates P, Blackman M, Cragg G, ...

  6. Licorice Root

    MedlinePLUS

    ... sweet root, gan zao (Chinese licorice) Latin Name: Glycyrrhiza glabra, Glycyrrhiza uralensis (Chinese licorice) licorice_foster.jpg © Steven Foster ... References Armanini D, Fiore C, Bielenberg J. Licorice ( Glycyrrhiza glabra ). In: Coates P, Blackman M, Cragg G, ...

  7. A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

    PubMed Central

    Oh, Chang Hyun; Shim, Yu Shik; Park, Hyeonseon

    2015-01-01

    Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques. PMID:25810866

  8. Aberrant gastrocnemius muscle innervation by tibial nerve afferents after implantation of chitosan tubes impregnated with progesterone favored locomotion recovery in rats with transected sciatic nerve.

    PubMed

    Sarabia-Estrada, Rachel; Bañuelos-Pineda, Jacinto; Osuna Carrasco, Laura P; Jiménez-Vallejo, Salvador; Jiménez-Estrada, Ismael; Rivas-Celis, Efrain; Dueñas-Jiménez, Judith M; Dueñas-Jiménez, Sergio H

    2015-07-01

    OBJECT Transection of peripheral nerves produces loss of sensory and/or motor function. After complete nerve cutting, the distal and proximal segment ends retract, but if both ends are bridged with unaltered chitosan, progesterone-impregnated chitosan, or silicone tubes, an axonal repair process begins. Progesterone promotes nerve repair and has neuroprotective effects thwarting regulation of neuron survival, inflammation, and edema. It also modulates aberrant axonal sprouting and demyelination. The authors compared the efficacy of nerve recovery after implantation of progesterone-loaded chitosan, unaltered chitosan, or silicone tubes after sciatic nerve transection in rats. METHODS After surgical removal of a 5-mm segment of the proximal sciatic nerve, rats were implanted with progesterone-loaded chitosan, unaltered chitosan, or silicone tubes in the transected nerve for evaluating progesterone and chitosan effects on sciatic nerve repair and ipsilateral hindlimb kinematic function, as well as on gastrocnemius electro-myographic responses. In some experiments, tube implantation was performed 90 minutes after nerve transection. RESULTS At 90 days after sciatic nerve transection and tube implantation, rats with progesterone-loaded chitosan tubes showed knee angular displacement recovery and better outcomes for step length, velocity of locomotion, and normal hindlimb raising above the ground. In contrast, rats with chitosan-only tubes showed reduced normal raising and pendulum-like hindlimb movements. Aberrant fibers coming from the tibial nerve innervated the gastrocnemius muscle, producing electromyographic responses. Electrical responses in the gastrocnemius muscle produced by sciatic nerve stimulation occurred only when the distal nerve segment was stimulated; they were absent when the proximal or intratubular segment was stimulated. A clear sciatic nerve morphology with some myelinated fiber fascicles appeared in the tube section in rats with progesterone-impregnated chitosan tubes. Some gastrocnemius efferent fibers were partially repaired 90 days after nerve resection. The better outcome in knee angle displacement may be partially attributable to the aberrant neuromuscular synaptic effects, since nerve conduction in the gastrocnemius muscle could be blocked in the progesterone-impregnated chitosan tubes. In addition, in the region of the gap produced by the nerve resection, the number of axons and amount of myelination were reduced in the sciatic nerve implanted with chitosan, progesterone-loaded chitosan, and silicone tubes. At 180 days after sciatic nerve sectioning, the knee kinematic function recovered to a level observed in control rats of a similar age. In rats with progesterone-loaded chitosan tubes, stimulation of the proximal and intratubular sciatic nerve segments produced an electromyographic response. The axon morphology of the proximal and intratubular segments of the sciatic nerve resembled that of the contralateral nontransected nerve. CONCLUSIONS Progesterone-impregnated chitosan tubes produced aberrant innervation of the gastrocnemius muscle, which allowed partial recovery of gait locomotion and could be adequate for reinnervating synergistic denervated muscles while a parent innervation is reestablished. Hindlimb kinematic parameters differed between younger (those at 90 days) and older (those at 180 days) rats. PMID:25679274

  9. Lentiviral Vector-Mediated Gradients of GDNF in the Injured Peripheral Nerve: Effects on Nerve Coil Formation, Schwann Cell Maturation and Myelination

    PubMed Central

    Eggers, Ruben; de Winter, Fred; Hoyng, Stefan A.; Roet, Kasper C. D.; Ehlert, Erich M.; Malessy, Martijn J. A.; Verhaagen, Joost; Tannemaat, Martijn R.

    2013-01-01

    Although the peripheral nerve is capable of regeneration, only a small minority of patients regain normal function after surgical reconstruction of a major peripheral nerve lesion, resulting in a severe and lasting negative impact on the quality of life. Glial cell-line derived neurotrophic factor (GDNF) has potent survival- and outgrowth-promoting effects on motoneurons, but locally elevated levels of GDNF cause trapping of regenerating axons and the formation of nerve coils. This phenomenon has been called the “candy store” effect. In this study we created gradients of GDNF in the sciatic nerve after a ventral root avulsion. This approach also allowed us to study the effect of increasing concentrations of GDNF on Schwann cell proliferation and morphology in the injured peripheral nerve. We demonstrate that lentiviral vectors can be used to create a 4 cm long GDNF gradient in the intact and lesioned rat sciatic nerve. Nerve coils were formed throughout the gradient and the number and size of the nerve coils increased with increasing GDNF levels in the nerve. In the nerve coils, Schwann cell density is increased, their morphology is disrupted and myelination of axons is severely impaired. The total number of regenerated and surviving motoneurons is not enhanced after the distal application of a GDNF gradient, but increased sprouting does result in higher number of motor axon in the distal segment of the sciatic nerve. These results show that lentiviral vector mediated overexpression of GDNF exerts multiple effects on both Schwann cells and axons and that nerve coil formation already occurs at relatively low concentrations of exogenous GDNF. Controlled expression of GDNF, by using a viral vector with regulatable GDNF expression, may be required to avoid motor axon trapping and to prevent the effects on Schwann cell proliferation and myelination. PMID:23951085

  10. Deficiency in monocarboxylate transporter 1 (MCT1) in mice delays regeneration of peripheral nerves following sciatic nerve crush.

    PubMed

    Morrison, Brett M; Tsingalia, Akivaga; Vidensky, Svetlana; Lee, Youngjin; Jin, Lin; Farah, Mohamed H; Lengacher, Sylvain; Magistretti, Pierre J; Pellerin, Luc; Rothstein, Jeffrey D

    2015-01-01

    Peripheral nerve regeneration following injury occurs spontaneously, but many of the processes require metabolic energy. The mechanism of energy supply to axons has not previously been determined. In the central nervous system, monocarboxylate transporter 1 (MCT1), expressed in oligodendroglia, is critical for supplying lactate or other energy metabolites to axons. In the current study, MCT1 is shown to localize within the peripheral nervous system to perineurial cells, dorsal root ganglion neurons, and Schwann cells by MCT1 immunofluorescence in wild-type mice and tdTomato fluorescence in MCT1 BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves of MCT1 heterozygous null mice are crushed and peripheral nerve regeneration was quantified electrophysiologically and anatomically. Compound muscle action potential (CMAP) recovery is delayed from a median of 21 days in wild-type mice to greater than 38 days in MCT1 heterozygote null mice. In fact, half of the MCT1 heterozygote null mice have no recovery of CMAP at 42 days, while all of the wild-type mice recovered. In addition, muscle fibers remain 40% more atrophic and neuromuscular junctions 40% more denervated at 42 days post-crush in the MCT1 heterozygote null mice than wild-type mice. The delay in nerve regeneration is not only in motor axons, as the number of regenerated axons in the sural sensory nerve of MCT1 heterozygote null mice at 4 weeks and tibial mixed sensory and motor nerve at 3 weeks is also significantly reduced compared to wild-type mice. This delay in regeneration may be partly due to failed Schwann cell function, as there is reduced early phagocytosis of myelin debris and remyelination of axon segments. These data for the first time demonstrate that MCT1 is critical for regeneration of both sensory and motor axons in mice following sciatic nerve crush. PMID:25447940

  11. Histochemical discrimination of fibers in regenerating rat infraorbital nerve

    NASA Technical Reports Server (NTRS)

    Wilke, R. A.; Riley, D. A.; Sanger, J. R.

    1992-01-01

    In rat dorsal root ganglia, histochemical staining of carbonic anhydrase (CA) and cholinesterase (CE) yields a reciprocal pattern of activity: Sensory processes are CA positive and CE negative, whereas motor processes are CA negative and CE positive. In rat infraorbital nerve (a sensory peripheral nerve), we saw extensive CA staining of nearly 100% of the myelinated axons. Although CE reactivity in myelinated axons was extremely rare, we did observe CE staining of unmyelinated autonomic fibers. Four weeks after transection of infraorbital nerves, CA-stained longitudinal sections of the proximal stump demonstrated 3 distinct morphological zones. A fraction of the viable axons retained CA activity to within 2 mm of the distal extent of the stump, and the stain is capable of resolving growth sprouts being regenerated from these fibers. Staining of unmyelinated autonomic fibers in serial sections shows that CE activity was not retained as far distally as is the CA sensory staining.

  12. Can amino-functionalized carbon nanotubes carry functional nerve growth factor?

    PubMed Central

    Chen, Wen; Xiong, Qing; Ren, Quanxia; Guo, Yake; Li, Gao

    2014-01-01

    Carbon nanotubes can carry protein into cells to induce biological effects. Amino-functionalized carbon nanotubes are soluble and biocompatible, have high reactivity and low toxicity, and can help promote nerve cell growth. In this study, amino-functionalized ethylenediamine-treated multi-walled carbon nanotubes were used to prepare carbon nanotubes-nerve growth factor complexes by non-covalent grafting. The physicochemical properties, cytotoxicity to PC12 and chick embryo dorsal root ganglion, and biological activity of the carbon nanotubes-nerve growth factor complexes were investigated. The results showed that amino functionalization improved carbon nanotubes-nerve growth factor complex dispersibility, reduced their toxicity to PC12 cells, and promoted PC12 cell differentiation and chick embryo dorsal root ganglion. PMID:25206814

  13. Adapting to variable prismatic displacement

    NASA Technical Reports Server (NTRS)

    Welch, Robert B.; Cohen, Malcolm M.

    1989-01-01

    In each of two studies, subjects were exposed to a continuously changing prismatic displacement with a mean value of 19 prism diopters (variable displacement) and to a fixed 19-diopter displacement (fixed displacement). In Experiment 1, significant adaptation (post-pre shifts in hand-eye coordination) was found for fixed, but not for variable, displacement. Experiment 2 demonstrated that adaptation was obtained for variable displacement, but it was very fragile and is lost if the measures of adaptation are preceded by even a very brief exposure of the hand to normal or near-normal vision. Contrary to the results of some previous studies, an increase in within-S dispersion was not found of target pointing responses as a result of exposure to variable displacement.

  14. Delayed loss of spinal motoneurons after peripheral nerve injury in adult rats: a quantitative morphological study

    Microsoft Academic Search

    Jianjun Ma; Lev N. Novikov; Mikael Wiberg; Jan-Olof Kellerth

    2001-01-01

    .   The existence of retrograde cell death in sensory dorsal root ganglion (DRG) cells after peripheral nerve injury is well\\u000a established. However, with respect to retrograde motoneuron death after peripheral nerve injury, available data are conflicting.\\u000a This may partly be due to the cell counting techniques used. In the present study, quantitative morphometric methods have\\u000a been used to analyse retrograde

  15. Sensory nerve conduction studies of the L-1\\/L-2 dorsal rami

    Microsoft Academic Search

    Amrit P. Singh; Hillel M. Sommer

    1996-01-01

    Objective: This report describes a technique for performing sensory nerve conduction studies of the lateral cutaneous branches of the dorsal rami of the L-1\\/L-2 nerve roots for use in the evaluation of unilateral low back pain without lower limb referral.Subjects: Eleven healthy adult volunteers (9 men and 2 women) ranging in age from 25 to 36 years with no current

  16. Peripheral nerve sheath tumor in a subadult golden eagle (Aquila chrysaetos).

    PubMed

    Wernick, Morena Bernadette; Dennler, Matthias; Beckmann, Kathrin; Schybli, Martina; Albini, Sarah; Hoop, Richard K; Steffen, Frank; Kircher, Patrick; Hatt, Jean-Michel

    2014-03-01

    A 5-year-old, female golden eagle (Aquila chrysaetos) was admitted with tetraplegia that progressed to a nonambulatory, spastic tetraparesis after a few days of treatment. Clinical and radiologic examinations, including radiography, computed tomography scan, and myelography, were indicative of neoplasia involving a spinal nerve root. Postmortem magnetic resonance imaging and necropsy findings confirmed the diagnosis of a peripheral nerve sheath neoplasia, not, to our knowledge, previously reported in a raptor. PMID:24881155

  17. Root fortification.

    PubMed

    Seghi, Robert R; Nasrin, Sadia; Draney, Jonathan; Katsube, Noriko

    2013-03-01

    An incompletely formed tooth is left with thin dentin walls and experiences a higher incidence of cervical root fracture that reduces the long-term overall prognosis of the tooth. Faced with these situations, clinicians have attempted to use various restorative methods to reinforce the remaining root. Various techniques have been reported, and the scientific evidence for each has been reviewed. The biomechanical considerations of reinforcing a weakened root are also reviewed, and the most current information about failure analysis, fracture characteristics of natural dentin, and in vitro test configurations used have been considered. In light of these additional considerations, some recommendations for future understanding of this complex problem have been proposed. PMID:23439045

  18. Myelinated Nerve Fibre, Myelin

    Microsoft Academic Search

    Margit Pavelka; Jürgen Roth

    \\u000a Nerve fibres designed for particularly rapid and efficient conduction of action potentials are equipped with a myelin sheath,\\u000a a lipid-enriched layer, produced by specialised glial cells, the oligodendrocytes in the central nervous system, and the Schwann\\u000a cells in the peripheral nervous system. The myelin sheath isolates the axon from the surrounding compartments. It reduces\\u000a the current flow across the axonal

  19. Methods of peripheral nerve tissue preparation for second harmonic generation imaging of collagen fibers.

    PubMed

    Vijayaraghavan, Surabhi; Huq, Rumana; Hausman, Michael R

    2014-03-15

    Second harmonic generation (SHG) imaging of the peripheral nerve using multi-photon microscopy is a novel technique with little documentation. It affords the significant possibility of non-destructive imaging of internal nerve anatomy. The nature of nerve tissue, especially its size and viscoelastic properties, present special challenges for microscopy. While nerves are under an innate in situ strain, they retract once dissected, thus distorting microscopic structure. The challenge is to preserve the nerve in its natural strain range to obtain images that most truly reveal its structure. This study examined backscattered SHG images of rat median nerve prepared by several different methods to compare image quality and content. Nerve segments were fixed under strained (constant load or length) and unstrained conditions and imaged as whole nerve as well as plastic (methyl methacrylate) and paraffin embedded sections. These were tested for optimal excitation wavelength, quantitative image contrast, and overall quality. Root mean squared (RMS) contrast proved to be a reliable measure of the level of image contrast perceived by eye. We concluded that images obtained from tissue sections (plastic and paraffin) provided the most accurate and revealing SHG images of peripheral nerve structure. Removing the embedding material prior to imaging significantly improved image quality. Optimal excitation wavelengths were consistent regardless of the preparation method. PMID:23962836

  20. Automated Root Tracking with "Root System Analyzer"

    NASA Astrophysics Data System (ADS)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent identification number, the distance between branching point to the parent root base, the root length, the root radius and the nodes that belong to each individual root path. This information is relevant for the analysis of dynamic root system development as well as the parameterisation of root architecture models. Here, we show results of Root System Analyzer applied to analyse the root systems of wheat plants grown in rhizotrons. Different treatments with respect to soil moisture and apatite concentrations were used to test the effects of those conditions on root system development. Photographs of the root systems were taken at high spatial and temporal resolution and root systems are automatically tracked.

  1. Displacement Parameter Inversion for a Novel Electromagnetic Underground Displacement Sensor

    PubMed Central

    Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

    2014-01-01

    Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named “EELA forward modeling-approximate inversion method”. Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0–100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

  2. Displacement parameter inversion for a novel electromagnetic underground displacement sensor.

    PubMed

    Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

    2014-01-01

    Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named "EELA forward modeling-approximate inversion method". Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0-100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

  3. Measuring vulnerability to disaster displacement

    NASA Astrophysics Data System (ADS)

    Brink, Susan A.; Khazai, Bijan; Power, Christopher; Wenzel, Friedemann

    2015-04-01

    Large scale disasters can cause devastating impacts in terms of population displacement. Between 2008 and 2013, on average 27 million people were displaced annually by disasters (Yonetani 2014). After large events such as hurricane Katrina or the Port-au-Prince earthquake, images of inadequate public shelter and concerns about large scale and often inequitable migration have been broadcast around the world. Population displacement can often be one of the most devastating and visible impacts of a natural disaster. Despite the importance of population displacement in disaster events, measures to understand the socio-economic vulnerability of a community often use broad metrics to estimate the total socio-economic risk of an event rather than focusing on the specific impacts that a community faces in a disaster. Population displacement is complex and multi-causal with the physical impact of a disaster interacting with vulnerability arising from the response, environmental issues (e.g., weather), cultural concerns (e.g., expectations of adequate shelter), and many individual factors (e.g., mobility, risk perception). In addition to the complexity of the causes, population displacement is difficult to measure because of the wide variety of different terms and definitions and its multi-dimensional nature. When we speak of severe population displacement, we may refer to a large number of displaced people, an extended length of displacement or associated difficulties such as poor shelter quality, risk of violence and crime in shelter communities, discrimination in aid, a lack of access to employment or other difficulties that can be associated with large scale population displacement. We have completed a thorough review of the literature on disaster population displacement. Research has been conducted on historic events to understand the types of negative impacts associated with population displacement and also the vulnerability of different groups to these impacts. We aggregate these ideas into a framework of disaster displacement vulnerability that distinguishes between three main aspects of disaster displacement. Disaster displacement can be considered in terms of the number of displaced people and the length of that displacement. However, the literature emphasizes that the severity of disaster displacement can not be measured completely in quantitative terms. Thus, we include a measure representing people who are trapped and unable to leave their homes due to mobility, resources or for other reasons. Finally the third main aspect considers the difficulties that are associated with displacement and reflects the difference between the experiences of those who are displaced into safe and supportive environments as compared to those whose only alternate shelter is dangerous and inadequate for their needs. Finally, we apply the framework to demonstrate a methodology to estimate vulnerability to disaster displacement. Using data from the Global Earthquake Model (GEM) Social and Economic Vulnerability sub-National Database, we generate an index to measure the vulnerability of Japanese prefectures to the dimensions of displacement included in the framework. References Yonitani, M. (2014). Global Estimates 2014: People displaced by disasters. http://www.internal-displacement.org/publications/2014/global-estimates-2014-people-displaced-by-disasters/

  4. Ultrasound guidance of uncommon nerve blocks

    PubMed Central

    Thallaj, Ahmed

    2011-01-01

    In the past nerve stimulation was considered the standard tool for anesthesiologists to locate the peripheral nerve for nerve blocks. However, with the recent introduction of ultrasound (US) technology for regional anesthesia, the use of nerve stimulation has become a rarity nowadays. There is a growing interest by most anesthesiologists in using US for nerve blocks because of its simplicity and accuracy. US is now available in most hospitals practicing regional anesthesia and is a popular tool for performance of nerve blocks. Although nerve stimulation became a rarity, however the use of it is now limited to identify small nerve structures, such as greater auricular nerve and medial antebrachial cutaneous nerve of the forearm. However, in this review article we discuss the role of ultrasonography for greater auricular and antebrachial cutaneous nerve blocks, which could replace nerve stimulation technique. We look at the available literature on the role of US for the performance of uncommon nerve blocks and its benefits. PMID:22144927

  5. Sixth cranial nerve palsy caused by compression from a dolichoectatic vertebral artery.

    PubMed

    Zhu, Ying; Thulborn, Keith; Curnyn, Kimberlee; Goodwin, James

    2005-06-01

    A 68-year-old man had an unremitting left sixth cranial nerve palsy immediately after completing a long bicycle trip. High-resolution (3 Tesla) magnetic resonance imaging disclosed a dolichoectatic vertebral artery that compressed the left sixth cranial nerve against the belly of the pons at its root exit zone. It was postulated that increased blood flow in the vessel during the unusually prolonged aerobic exercise precipitated the palsy. Compressive palsies of cranial nerves caused by a dolichoectatic basilar artery have often been documented; compressive palsy caused by a dolichoectatic vertebral artery is less well-recognized. PMID:15937439

  6. Strategies for displacing oil

    NASA Astrophysics Data System (ADS)

    Rao, Vikram; Gupta, Raghubir

    2015-03-01

    Oil currently holds a monopoly on transportation fuels. Until recently biofuels were seen as the means to break this stranglehold. They will still have a part to play, but the lead role has been handed to natural gas, almost solely due to the increased availability of shale gas. The spread between oil and gas prices, unprecedented in its scale and duration, will cause a secular shift away from oil as a raw material. In the transport fuel sector, natural gas will gain traction first in the displacement of diesel fuel. Substantial innovation is occurring in the methods of producing liquid fuel from shale gas at the well site, in particular in the development of small scale distributed processes. In some cases, the financing of such small-scale plants may require new business models.

  7. Neuromuscular Ultrasound of Cranial Nerves

    PubMed Central

    Tawfik, Eman A.; Cartwright, Michael S.

    2015-01-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed. PMID:25851889

  8. Synaptic Reorganization in the Substantia Gelatinosa After Peripheral Nerve Neuroma Formation: Aberrant Innervation of Lamina II Neurons by Ab Afferents

    Microsoft Academic Search

    Ikuhide Koham; Kuniko Ishikawa; Jeffery D. Kocsis

    2000-01-01

    Intracellular recording and extracellular field potential (FP) re- cordings were obtained from spinal cord dorsal horn neurons (laminae I-IV) in a rat transverse slice preparation with attached dorsal roots. To study changes in synaptic inputs after neuroma formation, the sciatic nerve was sectioned and ligated 3 weeks before in vitro electrophysiological analysis. Horseradish per- oxidase labeling of dorsal root axons

  9. Root gravitropism

    NASA Technical Reports Server (NTRS)

    Masson, P. H.

    1995-01-01

    When a plant root is reoriented within the gravity field, it responds by initiating a curvature which eventually results in vertical growth. Gravity sensing occurs primarily in the root tip. It may involve amyloplast sedimentation in the columella cells of the root cap, or the detection of forces exerted by the mass of the protoplast on opposite sides of its cell wall. Gravisensing activates a signal transduction cascade which results in the asymmetric redistribution of auxin and apoplastic Ca2+ across the root tip, with accumulation at the bottom side. The resulting lateral asymmetry in Ca2+ and auxin concentration is probably transmitted to the elongation zone where differential cellular elongation occurs until the tip resumes vertical growth. The Cholodny-Went theory proposes that gravity-induced auxin redistribution across a gravistimulated plant organ is responsible for the gravitropic response. However, recent data indicate that the gravity-induced reorientation is more complex, involving both auxin gradient-dependent and auxin gradient-independent events.

  10. Neurotrophin releasing single and multiple lumen nerve conduits

    PubMed Central

    Yang, Yang; De Laporte, Laura; Rives, Christopher B.; Jang, Jae-Hyung; Lin, Wei-Chun; Shull, Kenneth R.; Shea, Lonnie D.

    2008-01-01

    Tissue engineering strategies for nerve repair employ polymer conduits termed guidance channels and bridges to promote regeneration for peripheral nerve injury and spinal cord injury, respectively. An approach for fabrication of nerve conduits with single and multiple lumens capable of controlled release of neurotrophic factors was developed. These conduits were fabricated from a mixture of poly(lactide-co-glycolide) (PLG) microspheres and porogen (NaCl) that was loaded into a mold and processed by gas foaming. The porosity and mechanical properties of the constructs were regulated by the ratio of porogen to polymer microsphere. The neurotrophin, nerve growth factor (NGF), was incorporated into the conduit by either mixing the protein with microspheres or encapsulating the protein within microspheres prior to gas foaming. A sustained release was observed for at least 42 days, with the release rate controlled by method of incorporation and polymer molecular weight. Released NGF retained its bioactivity, as demonstrated by its ability to stimulate neurite outgrowth from primary dorsal root ganglion (DRG). In vivo results indicate that conduits retain their original architecture, and allow for cellular infiltration into the channels. Polymer conduits with controllable lumen diameters and protein release may enhance nerve regeneration by guiding and stimulating neurite outgrowth. PMID:15911044

  11. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  12. Mutations affecting nerve attachment of Caenorhabditis elegans.

    PubMed Central

    Shioi, G; Shoji, M; Nakamura, M; Ishihara, T; Katsura, I; Fujisawa, H; Takagi, S

    2001-01-01

    Using a pan-neuronal GFP marker, a morphological screen was performed to detect Caenorhabditis elegans larval lethal mutants with severely disorganized major nerve cords. We recovered and characterized 21 mutants that displayed displacement or detachment of the ventral nerve cord from the body wall (Ven: ventral cord abnormal). Six mutations defined three novel genetic loci: ven-1, ven-2, and ven-3. Fifteen mutations proved to be alleles of previously identified muscle attachment/positioning genes, mup-4, mua-1, mua-5, and mua-6. All the mutants also displayed muscle attachment/positioning defects characteristic of mua/mup mutants. The pan-neuronal GFP marker also revealed that mutants of other mua/mup loci, such as mup-1, mup-2, and mua-2, exhibited the Ven defect. The hypodermis, the excretory canal, and the gonad were morphologically abnormal in some of the mutants. The pleiotropic nature of the defects indicates that ven and mua/mup genes are required generally for the maintenance of attachment of tissues to the body wall in C. elegans. PMID:11290717

  13. Magnetic property of the nerve.

    PubMed

    Varga, L; Barrett, J S; Keszthelyi, L; Madarász, E

    1978-01-01

    An electromagnet of inhomogeneous magneticfield has been used to measure the magnetic susceptibility of the frog's nerve. Specimen of frog sciatic nerve were attached to a thin tungsten wire hanging into the inhomogeneous magnetic field, and from the deviation of this pendulum from the perpendicular position the magnetic susceptibility of the nerve has been determined to be -0.8 . 10(-6) cm3g-1 in a good agreement with the known magnetic property of the constituents of the nerve. PMID:754499

  14. Nerve Agents: A Comprehensive Review

    Microsoft Academic Search

    Sage W. Wiener; Robert S. Hoffman

    2004-01-01

    Nerve agents are perhaps the most feared of potential agents of chemical attack. The authors review the history, physical characteristics, pharmacology, clinical effects, and treatment of these agents.

  15. Facial nerve neuromas: radiologic evaluation.

    PubMed

    Latack, J T; Gabrielsen, T O; Knake, J E; Kemink, J L; Graham, M D; Gebarski, S S; Yang, P J

    1983-12-01

    Eight patients who had facial nerve neuromas were examined, and the radiographic findings are reported. Thin section tomography, high resolution computed tomography, posterior fossa computed tomography, and cerebellopontine angle cisternography using Pantopaque (iophendylate) demonstrated bone erosions and soft tissue masses conforming to the course of the facial nerve. The lesions generally exhibited either a proximal or a distal pattern of nerve involvement. Radiologic imaging frequently permits a correct preoperative diagnosis and accurate definition of the extent of facial nerve neuromas, assessments that are important for proper patient management. PMID:6606188

  16. Nerve conduction and electromyography studies.

    PubMed

    Kane, N M; Oware, A

    2012-07-01

    Nerve conduction studies (NCS) and electromyography (EMG), often shortened to 'EMGs', are a useful adjunct to clinical examination of the peripheral nervous system and striated skeletal muscle. NCS provide an efficient and rapid method of quantifying nerve conduction velocity (CV) and the amplitude of both sensory nerve action potentials (SNAPs) and compound motor action potentials (cMAPs). The CV reflects speed of propagation of action potentials, by saltatory conduction, along large myelinated axons in a peripheral nerve. The amplitude of SNAPs is in part determined by the number of axons in a sensory nerve, whilst amplitude of cMAPs reflects integrated function of the motor axons, neuromuscular junction and striated muscle. Repetitive nerve stimulation (RNS) can identify defects of neuromuscular junction (NMJ) transmission, pre- or post-synaptic. Needle EMG examination can detect myopathic changes in muscle and signs of denervation. Combinations of these procedures can establish if motor and/or sensory nerve cell bodies or peripheral nerves are damaged (e.g. motor neuronopathy, sensory ganglionopathy or neuropathy), and also indicate if the primary target is the axon or the myelin sheath (i.e. axonal or demyelinating neuropathies). The distribution of nerve damage can be determined as either generalised, multifocal (mononeuropathy multiplex) or focal. The latter often due to compression at the common entrapment sites (such as the carpal tunnel, Guyon's canal, cubital tunnel, radial groove, fibular head and tarsal tunnel, to name but a few of the reported hundred or so 'entrapment neuropathies'). PMID:22614870

  17. The near-nerve sensory nerve conduction in tarsal tunnel syndrome

    Microsoft Academic Search

    S J Oh; H S Kim; B K Ahmad

    1985-01-01

    The near-nerve sensory nerve conduction in the medial and lateral plantar nerves was studied in 25 cases of tarsal tunnel syndrome. Sensory nerve conduction was abnormal in 24 cases (96%) The most common abnormalities were slow nerve conduction velocities and dispersion phenomenon (prolonged duration of compound nerve action potentials). These two electrophysiological abnormalities are indicative of a focal segmental demyelination

  18. An analytical fiber bundle model for pullout mechanics of root bundles

    NASA Astrophysics Data System (ADS)

    Cohen, D.; Schwarz, M.; Or, D.

    2011-09-01

    Roots in soil contribute to the mechanical stability of slopes. Estimation of root reinforcement is challenging because roots form complex biological networks whose geometrical and mechanical characteristics are difficult to characterize. Here we describe an analytical model that builds on simple root descriptors to estimate root reinforcement. Root bundles are modeled as bundles of heterogeneous fibers pulled along their long axes neglecting root-soil friction. Analytical expressions for the pullout force as a function of displacement are derived. The maximum pullout force and corresponding critical displacement are either derived analytically or computed numerically. Key model inputs are a root diameter distribution (uniform, Weibull, or lognormal) and three empirical power law relations describing tensile strength, elastic modulus, and length of roots as functions of root diameter. When a root bundle with root tips anchored in the soil matrix is pulled by a rigid plate, a unique parameter, ?, that depends only on the exponents of the power law relations, dictates the order in which roots of different diameters break. If ? < 1, small roots break first; if ? > 1, large roots break first. When ? = 1, all fibers break simultaneously, and the maximum tensile force is simply the roots' mean force times the number of roots in the bundle. Based on measurements of root geometry and mechanical properties, the value of ? is less than 1, usually ranging between 0 and 0.7. Thus, small roots always fail first. The model shows how geometrical and mechanical characteristics of roots and root diameter distribution affect the pullout force, its maximum and corresponding displacement. Comparing bundles of roots that have similar mean diameters, a bundle with a narrow variance in root diameter will result in a larger maximum force and a smaller displacement at maximum force than a bundle with a wide diameter distribution. Increasing the mean root diameter of a bundle without changing the distribution's shape increases both the maximum force and corresponding displacement. Estimates of the maximum pullout forces for bundles of 100 roots with identical diameter distribution for different species range from less than 1 kN for barley (Hordeum vulgare) to almost 16 kN for pistachio (Pistacia lentiscus). The model explains why a commonly used assumption that all roots break simultaneously overpredicts the maximum pullout force by a factor of about 1.6-2. This ratio may exceed 3 for diameter distributions that have a large number of small roots like the exponential distribution.

  19. Robotic excision of a pre-coccygeal nerve root tumor.

    PubMed

    Palep, Jaydeep H; Mistry, Sheetal; Kumar, Abhaya; Munshi, Mihir; Puranik, Meenakshi; Pednekar, Abhinav

    2015-01-01

    Pre-coccygeal ganglioneuroma is a rare clinical entity that presents incidentally or with non-specific symptoms. We present a case of a 25 year old housewife who was incidentally diagnosed with pre-coccygeal ganglioneuroma while getting investigated for primary infertility. The patient had no specific complaints except for irregular menstruation which had started 8 months back. Magnetic resonance imaging (MRI) was suggestive of a presacral and pre-coccygeal lesion. Resection of the tumor was done through the anterior approach using the da Vinci Si robotic system. Two robotic arms and one assistant port were used to completely excise the tumor. Robotic excision of such a tumor mass located at a relatively inaccessible area allows enhanced precision and 3-dimentional (3D) view avoiding damage to important surrounding structures. PMID:25598609

  20. Robotic excision of a pre-coccygeal nerve root tumor

    PubMed Central

    Palep, Jaydeep H.; Mistry, Sheetal; Kumar, Abhaya; Munshi, Mihir; Puranik, Meenakshi; Pednekar, Abhinav

    2015-01-01

    Pre-coccygeal ganglioneuroma is a rare clinical entity that presents incidentally or with non-specific symptoms. We present a case of a 25 year old housewife who was incidentally diagnosed with pre-coccygeal ganglioneuroma while getting investigated for primary infertility. The patient had no specific complaints except for irregular menstruation which had started 8 months back. Magnetic resonance imaging (MRI) was suggestive of a presacral and pre-coccygeal lesion. Resection of the tumor was done through the anterior approach using the da Vinci Si robotic system. Two robotic arms and one assistant port were used to completely excise the tumor. Robotic excision of such a tumor mass located at a relatively inaccessible area allows enhanced precision and 3-dimentional (3D) view avoiding damage to important surrounding structures. PMID:25598609

  1. The extent of cytokine induction in peripheral nerve lesions depends on the mode of injury and NMDA receptor signaling.

    PubMed

    Kleinschnitz, C; Brinkhoff, J; Zelenka, M; Sommer, C; Stoll, G

    2004-04-01

    We compared cytokine and chemokine induction in mice after sciatic nerve crush and chronic constriction injury (CCI) by quantitative reverse transcriptase polymerase chain reaction. In both nerve lesion paradigms, transcripts for tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, IL-10, and monocyte chemoattractant protein-1 (MCP-1) were significantly increased in degenerating nerve stumps already at day 1, with a greater magnitude and longer duration in CCI. NMDA receptor blockade significantly reduced cytokine expression after CCI on the mRNA and protein level. In dorsal root ganglia, only IL-10 mRNA levels were modified after nerve injury. Our study indicates that the mode of nerve injury influences the extent of cytokine expression, and identifies NMDA-mediated signaling as one mechanism of cytokine induction in peripheral nerves. PMID:15020067

  2. Nervous System, Neurons, Nerves

    NSDL National Science Digital Library

    How does the nervous system work? It is a question that has engaged the minds of scientists, doctors, and others for centuries. The National Science Teachers Association (NSTA) has created this tour of the nervous system for teachers and students. First-time visitors can start with the Explore a Nerve Cell area, which goes over the membrane, nucleus, axon, dendrites, and the synapse in exquisite detail with interactive graphics. Moving on, The Basics area provides summaries of the operation of the nervous system and a rather illustrative area named Ouch! The site is rounded out by the Nervous Systems Explorations section, which has some nice simulations covering Brainstorms and Simple Reflexes.

  3. Demyelinating hypertrophic inferior alveolar nerve mimicking a nerve tumor.

    PubMed

    Fujita, Hiroaki; Kokubun, Norito; Sada, Tsubasa; Nagashima, Takahide; Komagamine, Tomoko; Kawabe, Kiyokazu; Hirata, Koichi

    2015-01-01

    We herein report a patient with demyelinating inferior alveolar nerve hypertrophy, which was initially suspected to have a nerve tumor. A 39-year-old woman with childhood-onset polyneuropathy presented with tooth pain and visited a dental clinic. An X-ray examination of the mandible revealed enlargement of the mandibular canal, and a nerve tumor was suspected. CT scan and MRI showed hypertrophy of the inferior alveolar nerve along its entire length. We diagnosed the patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), which was supported by the spontaneous recovery reported in her childhood, the results from a nerve conduction study and MRI data. CIDP should be considered in the differential diagnosis of mandibular canal enlargement. PMID:25948359

  4. Connecting localized DNA strand displacement reactions.

    PubMed

    Mullor Ruiz, Ismael; Arbona, Jean-Michel; Lad, Amitkumar; Mendoza, Oscar; Aimé, Jean-Pierre; Elezgaray, Juan

    2015-07-23

    Logic circuits based on DNA strand displacement reactions have been shown to be versatile enough to compute the square root of four-bit numbers. The implementation of these circuits as a set of bulk reactions faces difficulties which include leaky reactions and intrinsically slow, diffusion-limited reaction rates. In this paper, we consider simple examples of these circuits when they are attached to platforms (DNA origamis). As expected, constraining distances between DNA strands leads to faster reaction rates. However, it also induces side-effects that are not detectable in the solution-phase version of this circuitry. Appropriate design of the system, including protection and asymmetry between input and fuel strands, leads to a reproducible behaviour, at least one order of magnitude faster than the one observed under bulk conditions. PMID:26168352

  5. Regenerative rotary displacer Stirling engine

    Microsoft Academic Search

    Naotsugu Isshiki; Luca Raggi; S. Isshiki; K. Hirata; H. Watanabe

    1996-01-01

    A few rotary displacer Stirling engines whose displacers have one gas pocket space at one side, and rotate in a main enclosed cylinder, which is heated from one side and cooled from the opposite side without any regenerator have been tried and studied for a considerable time by the authors. They then tried to improve this engine by equipping them

  6. The Optical Stretcher Nerve Regeneration

    E-print Network

    Steiner, Ullrich

    standing paradigm that neurons in the CNS cannot regenerate is gone (after 3500 years). While most research!"# $ %& ' "!((! )# The Optical Stretcher Nerve Regeneration Cells as Optical Fibres Novel Imaging present after neurological trauma to see whether those pose mechanical barriers to nerve regeneration. We

  7. Temporal Adaptation Silicon Auditory Nerve

    E-print Network

    Lazzaro, John

    Temporal Adaptation in a Silicon Auditory Nerve John Lazzaro CS Division UC Berkeley 571 Evans Hall Berkeley, CA 94720 Abstract Many auditory theorists consider the temporal adaptation of the auditory nerve localization and pitch perception also suggest temporal adaptation is an important ele- ment of practical

  8. NERVE INJURY AFTER LAPAROSCOPIC VARICOCELECTOMY

    Microsoft Academic Search

    KRISTIN CHROUSER; DAVID VANDERSTEEN; JULIE CROCKER; YURI REINBERG

    2004-01-01

    Purpose:Laparoscopic varicocelectomy is a minimally invasive option for varicoceles in children. Occasional reports of nerve injury after inguinal laparoscopic procedures have been published. There is anatomical variation in the sensory innervation of the anterior thigh and variable branching patterns of the nerves involved. We report a retrospective analysis of our patients, focusing on the incidence of sensory changes on the

  9. Lesions of the optic nerve

    Microsoft Academic Search

    Edward J. Atkins; Nancy J. Newman; Valerie Biousse

    2011-01-01

    As experts on the central nervous system, neurologists are expected to be familiar with the many conditions that can result in visual loss arising from lesions of the optic nerve. The optic nerves are unique central nervous system structures in terms of surrounding anatomy, size, location, and blood supply; therefore, they are uniquely vulnerable to every pathological process that can

  10. Nerve Regeneration After Radiofrequency Application

    Microsoft Academic Search

    Nobuyasu Ochiai; James P. Tasto; Seiji Ohtori; Norimasa Takahashi; Hideshige Moriya; David Amiel

    Background: Many patients with chronic tendinosis have experienced early pain relief after application of bipolar radiofrequency treatment. It is hypothesized that the mechanism of action may be the acute degeneration and\\/or ablation of sensory nerve fibers. Hypothesis: After ablation or degeneration by bipolar radiofrequency, nerve fibers will have the ability to regenerate with time. Study Design: Controlled laboratory study. Methods:

  11. Adipose derived stem cells and nerve regeneration

    PubMed Central

    Faroni, Alessandro; Smith, Richard JP; Reid, Adam J

    2014-01-01

    Injuries to peripheral nerves are common and cause life-changing problems for patients alongside high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacrificing a section of nerve from elsewhere in the body to provide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacrifice of a functional nerve. Stem cells are prime candidates as accelerators of regeneration in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts. PMID:25221589

  12. Peripheral nerve lengthening as a regenerative strategy

    PubMed Central

    Vaz, Kenneth M.; Brown, Justin M.; Shah, Sameer B.

    2014-01-01

    Peripheral nerve injury impairs motor, sensory, and autonomic function, incurring substantial financial costs and diminished quality of life. For large nerve gaps, proximal lesions, or chronic nerve injury, the prognosis for recovery is particularly poor, even with autografts, the current gold standard for treating small to moderate nerve gaps. In vivo elongation of intact proximal stumps towards the injured distal stumps of severed peripheral nerves may offer a promising new strategy to treat nerve injury. This review describes several nerve lengthening strategies, including a novel internal fixator device that enables rapid and distal reconnection of proximal and distal nerve stumps. PMID:25317163

  13. Nerve injury induces the expression of syndecan-1 heparan sulfate proteoglycan in primary sensory neurons.

    PubMed

    Murakami, K; Tanaka, T; Bando, Y; Yoshida, S

    2015-08-01

    Heparan sulfate proteoglycans (HSPGs) have important functions in development of the central nervous system; however, their functions in nerve injury are not yet fully understood. We previously reported the expression of syndecan-1, a type of HSPG, in cranial motor neurons after nerve injury, suggesting the importance of syndecan-1 in the pathology of motor nerve injury. In this study, we examined the expression of syndecan-1, a type of HSPG, in primary sensory neurons after nerve injury in mice. Sciatic nerve axotomy strongly induced the expression of syndecan-1 in a subpopulation of injured dorsal root ganglion (DRG) neurons, which were small in size and had CGRP- or isolectin B4-positive fibers. Syndecan-1 was also distributed in the dorsal horn of the spinal cord ipsilateral to the axotomy, and located on the membrane of axons in lamina II of the dorsal horn. Not only sciatic nerve axotomy, infraorbital nerve axotomy also induced the expression of syndecan-1 in trigeminal ganglion neurons. Moreover, syndecan-1 knockdown in cultured DRG neurons induced a shorter neurite extension. These results suggest that syndecan-1 expression in injured primary sensory neurons may have functional roles in nerve regeneration and synaptic plasticity, resulting in the development of neuropathic pain. PMID:26002314

  14. Somatotopic fascicular organization of the human sciatic nerve demonstrated by MR neurography

    PubMed Central

    Weiler, Markus; Bendszus, Martin; Pham, Mirko

    2015-01-01

    Objectives: To investigate whether the human sciatic nerve might have a consistent somatotopic organization according to proximal fascicle input by spinal nerves. Methods: Twelve patients (55.3 ± 15.5 years) with confirmed lesions of either the L5 or S1 spinal nerve root underwent magnetic resonance neurography of sciatic nerve fascicles including thigh and knee levels (T2-weighted sequence with fat saturation, repetition time/echo time 7,552/52 milliseconds, voxel size 0.27 × 0.27 × 3.0 mm3). Twenty healthy subjects and 12 additional patients with an established diagnosis of peripheral polyneuropathy served as 2 separate age- and sex-matched control groups. Two blinded readers assessed patients and controls for presence of distinct lesion patterns. Spatial maps of normalized T2 signal were rendered after segmentation and coregistration of sciatic nerve voxels to detect fascicle lesion patterns. Results: A clear somatotopic distribution of nerve fascicles was observed on cross-sections along the entire course of the sciatic nerve and was distinct between patients with L5 and those with S1 lesions. Fascicles emerging from L5 were ordered in anterolateral positions within sciatic nerve cross-sections, while fascicles emerging from S1 appeared posteromedially. Visual assessment discriminated these somatotopic lesions in all cases from both healthy and polyneuropathy controls. Conclusion: A distinct pattern of somatotopy was identified within the sciatic nerve according to proximal fascicle input by L5 and S1 spinal nerves. Knowledge of human nerve somatotopy may have clinically useful implications in imaging-aided diagnosis of neuropathies. PMID:25841030

  15. Root Communication: The Role of Root Exudates

    Microsoft Academic Search

    B. Prithiviraj; Mark W. Paschke; Jorge M. Vivanco

    Plants communicate with neighboring plants and other organisms surrounding them. Aboveground communication isarticulatedthroughstems,leaves,orflowerswhilebelow-groundcommunication ismedi- ated by roots. The plant root is capable of secreting chemicals into the rhizosphere through root exudates. Thechemicalconstituentsoftherootexudatesarecharacteristicofaparticularplantspeciesandalsodepend on the surrounding biotic and abiotic environment. Recent research suggests that the root exudates act as a sort of chemical 'language' between the secreting plant and other organisms

  16. Systemic anti-inflammatory effect induced by antidromic stimulation of the dorsal roots in the rat

    Microsoft Academic Search

    Erika Pintér; János Szolcsányi

    1996-01-01

    Neurogenic inflammation and other local efferent functions of the capsaicin-sensitive nerve endings is well established. Here, we describe evidence for a systemic neurogenic anti-inflammatory effect initiated in the rat by this local response. A preceding local neurogenic inflammatory induced by antidromic stimulation of lumbar dorsal roots inhibited a subsequent inflammatory response due to antidromic stimulation of the contralateral dorsal roots

  17. Neurotrophin3 administration alters neurotrophin, neurotrophin receptor and nestin mRNA expression in rat dorsal root ganglia following axotomy

    Microsoft Academic Search

    L.-T. Kuo; M. J. Groves; F. Scaravilli; D. Sugden; S. F. An

    2007-01-01

    In the months following transection of adult rat peripheral nerve some sensory neurons undergo apoptosis. Two weeks after sciatic nerve transection some neurons in the L4 and L5 dorsal root ganglia begin to show immunoreactivity for nestin, a filament protein expressed by neuronal precursors and immature neurons, which is stimulated by neurotrophin-3 (NT-3) administration. The aim of this study was

  18. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...205.153 Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the nearest whole...Materials (ASTM) E 29-67. (b) For rotary engines, displacement means the maximum...

  19. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...205.153 Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the nearest whole...Materials (ASTM) E 29-67. (b) For rotary engines, displacement means the maximum...

  20. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...205.153 Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the nearest whole...Materials (ASTM) E 29-67. (b) For rotary engines, displacement means the maximum...

  1. Displacement sensing system and method

    DOEpatents

    VunKannon, Jr., Robert S

    2006-08-08

    A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

  2. Protein-water displacement distributions.

    PubMed

    Doster, Wolfgang; Settles, Marcus

    2005-06-01

    The statistical properties of fast protein-water motions are analyzed by dynamic neutron scattering experiments. Using isotopic exchange, one probes either protein or water hydrogen displacements. A moment analysis of the scattering function in the time domain yields model-independent information such as time-resolved mean square displacements and the Gauss-deviation. From the moments, one can reconstruct the displacement distribution. Hydration water displays two dynamical components, related to librational motions and anomalous diffusion along the protein surface. Rotational transitions of side chains, in particular of methyl groups, persist in the dehydrated and in the solvent-vitrified protein structure. The interaction with water induces further continuous protein motions on a small scale. Water acts as a plasticizer of displacements, which couple to functional processes such as open-closed transitions and ligand exchange. PMID:15893505

  3. Nerve Growth Factor Enhances Calcitonin Gene-Related Peptide Expression in the Spontaneously Hypertensive Rat

    Microsoft Academic Search

    Scott C. Supowit; Huawei Zhao; Donald J. DiPette

    2010-01-01

    Calcitonin gene-related peptide (CGRP) expression is markedly reduced in dorsal root ganglia neurons in the spontaneously hypertensive rat (SHR). This decrease in such a potent vasodilator may contribute to the elevated blood pressure. Therefore, the purpose of this study was to determine whether stimulation of neuronal CGRP expression in SHR, by means of the administration of nerve growth factor, would

  4. Silk-tropoelastin protein films for nerve guidance.

    PubMed

    White, James D; Wang, Siran; Weiss, Anthony S; Kaplan, David L

    2015-03-01

    Peripheral nerve regeneration may be enhanced through the use of biodegradable thin film biomaterials as highly tuned inner nerve conduit liners. Dorsal root ganglion neuron and Schwann cell responses were studied on protein films comprising silk fibroin blended with recombinant human tropoelastin protein. Tropoelastin significantly improved neurite extension and enhanced Schwann cell process length and cell area, while the silk provided a robust biomaterial template. Silk-tropoelastin blends afforded a 2.4-fold increase in neurite extension, when compared to silk films coated with poly-d-lysine. When patterned by drying on grooved polydimethylsiloxane (3.5 ?m groove width, 0.5 ?m groove depth), these protein blends induced both neurite and Schwann cell process alignment. Neurons were functional as assessed using patch-clamping, and displayed action potentials similar to those cultured on poly(lysine)-coated glass. Taken together, silk-tropoelastin films offer useful biomaterial interfacial platforms for nerve cell control, which can be considered for neurite guidance, disease models for neuropathies and surgical peripheral nerve repairs. PMID:25481743

  5. Nerve Agents ATSDR ? General Information 1

    E-print Network

    Baloh, Bob

    Nerve Agents ATSDR ? General Information 1 Nerve Agents Tabun (GA) CAS 77-81-6; Sarin (GB) CAS 107-diisopropylaminoethyl methylphosphonothiolate ? Persons whose skin or clothing is contaminated with nerve agent can contaminate rescuers by direct contact orthrough off-gassing vapor. Persons whose skin is exposed only to nerve agent vapor pose

  6. Endometriotic lesions of the lower troncular nerves.

    PubMed

    Niro, J; Fournier, M; Oberlin, C; Le Tohic, A; Panel, P

    2014-10-01

    Although exceptional, endometriotic lesions of the troncular nerves of the lower limb may occur and are often diagnosed with delay. We report, hereby, the first case of femoral nerve endometriosis the treatment of which consisted of radical resection with femoral nerve transplant. We completed a review of the literature on sciatic nerve endometriotic lesions and discussed the physiopathology and surgical treatment. PMID:25267476

  7. Geometric Deformation-Displacement Maps

    Microsoft Academic Search

    Gershon Elber

    2002-01-01

    Texture mapping, bump mapping, and displacement maps are central instruments in computer graphics aiming to achieve photo-realistic renderings. In all these techniques, the mapping is typically one-to-one and a single surface location is assigned a single texture color, normal, or displacement. Other specialized techniques have also been developed for the rendering of supplementary surface details such as fur hair, or

  8. Distribution of sodium channels during nerve elongation in rat peripheral nerve

    Microsoft Academic Search

    Harumitsu Ichimura; Takashi Shiga; Ichiro Abe; Yuki Hara; Naoto Terui; Akihito Tsujino; Naoyuki Ochiai

    2005-01-01

    A number of studies have investigated electrophysiological and morphological changes of peripheral nerves during gradual elongation. There has been, however, no report on the distribution of sodium channels at Ranvier’s nodes during peripheral nerve elongation. We investigated peripheral nerve injury after the gradual elongation of rat sciatic nerves. Indirect nerve elongation was induced by leg lengthening at a rate of

  9. Sciatic nerve regeneration is not inhibited by anti-NGF antibody treatment in the adult rat.

    PubMed

    Lankford, K L; Arroyo, E J; Liu, C-N; Somps, C J; Zorbas, M A; Shelton, D L; Evans, M G; Hurst, S I; Kocsis, J D

    2013-06-25

    Elevated nerve growth factor (NGF) is believed to play a role in many types of pain. An NGF-blocking antibody (muMab 911) has been shown to reduce pain and hyperalgesia in pain models, suggesting a novel therapeutic approach for pain management. Since NGF also plays important roles in peripheral nervous system development and sensory nerve outgrowth, we asked whether anti-NGF antibodies would adversely impact peripheral nerve regeneration. Adult rats underwent a unilateral sciatic nerve crush to transect axons and were subcutaneously dosed weekly for 8weeks with muMab 911 or vehicle beginning 1day prior to injury. Plasma levels of muMab 911 were assessed from blood samples and foot print analysis was used to assess functional recovery. At 8-weeks post-nerve injury, sciatic nerves were prepared for light and electron microscopy. In a separate group, Fluro-Gold was injected subcutaneously at the ankle prior to perfusion, and counts and sizes of retrogradely labeled and unlabeled dorsal root ganglion neurons were obtained. There was no difference in the time course of gait recovery in antibody-treated and vehicle-treated animals. The number of myelinated and nonmyelinated axons was the same in the muMab 911-treated crushed nerves and intact nerves, consistent with observed complete recovery. Treatment with muMab 911 did however result in a small decrease in average cell body size on both the intact and injured sides. These results indicate that muMab 911 did not impair functional recovery or nerve regeneration after nerve injury in adult rats. PMID:23531437

  10. Bone Augmentation and Nerve Repositioning

    MedlinePLUS

    ... Types of Bone-Augmentation Procedures Nerve Repositioning For dental implants to be successful, the jawbone must have enough ... of procedures used to "build" bone so that dental implants can be placed. These procedures typically involve grafting ( ...

  11. Ion Channels in Nerve Membranes

    ERIC Educational Resources Information Center

    Ehrenstein, Gerald

    1976-01-01

    Discusses research that indicates that nerve membranes, which play a key role in the conduction of impulses, are traversed by protein channels with ion pathways opened and closed by the membrane electric field. (Author/MLH)

  12. Selective measurement of digital nerve conduction velocity

    Microsoft Academic Search

    Yuji Terai; Masuo Senda; Hiroyuki Hashizume; Hiroaki Nagashima; Hajime Inoue

    2001-01-01

    We developed a new method to measure the nerve conduction velocity of a single digital nerve. In 27 volunteers (27 hands),\\u000a we separately stimulated each digital nerve on the radial and ulnar sides of the middle and ring fingers. A double-peaked\\u000a potential was recorded above the median nerve at the wrist joint when either the radial-side nerve or the ulnar-side

  13. Nerve Regeneration After Radiofrequency Application

    Microsoft Academic Search

    Nobuyasu Ochiai; James P. Tasto; Seiji Ohtori; Norimasa Takahashi; Hideshige Moriya; David Amiel

    2007-01-01

    Background: Many patients with chronic tendinosis have experienced early pain relief after application of bipolar radiofrequency treatment. It is hypothesized that the mechanism of action may be the acute degeneration and\\/or ablation of sensory nerve fibers.Hypothesis: After ablation or degeneration by bipolar radiofrequency, nerve fibers will have the ability to regenerate with time.Study Design: Controlled laboratory study.Methods: Eighteen Sprague-Dawley rats

  14. Adenosine triphosphatase in nerves and ganglia of rats with streptozotocin-induced diabetes or galactosaemia; effects of aldose reductase inhibition

    Microsoft Academic Search

    J. E. Lambourne; A. M. Brown; N. Calcutt; D. R. Tomlinson; G. B. Willars

    1988-01-01

    Summary  This study measured the ouabain-sensitive and ouabain-resistant adenosine triphosphatase activity in homogenates of the sciatic\\u000a nerves and of pooled fourth and fifth lumbar dorsal root ganglia from rats fed 20% galactose or made diabetic with streptozotocin\\u000a for either 4 or 8 weeks. Diabetes caused reductions in both fractions of sciatic nerve adenosine triphosphatase activity.\\u000a After 8 weeks the ouabainsensitive fraction

  15. MicroRNA machinery responds to peripheral nerve lesion in an injury-regulated pattern

    PubMed Central

    Wu, Di; Raafat, Mohamed; Pak, Elena; Hammond, Scott; Murashov, Alexander K.

    2011-01-01

    Recently, functional and potent RNA interference (RNAi) has been reported in peripheral nerve axons transfected with short-interfering RNA (siRNA). In addition, components of RNA-induced silencing complex (RISC) have been identified in axotomized sciatic nerve fibers as well as in regenerating dorsal root ganglia (DRG) neurons in vitro. Based on these observations, and on the fact that siRNA and microRNAs (miRNA) share the same effector enzymes, we hypothesized that the endogenous miRNA biosynthetic pathway would respond to peripheral nerve injury. To answer this question, we investigated changes in the expression of miRNA biosynthetic enzymes following peripheral nerve crush injury in mice. Here we show that several pivotal miRNA biosynthetic enzymes are expressed in an injury-regulated pattern in sciatic nerve in vivo, and in DRG axons in vitro. Moreover, the sciatic nerve lesion induced expression of mRNA-processing bodies (P-bodies), which are the local foci of mRNA degradation in DRG axons. In addition, a group of injury-regulated miRNAs was identified by miRNA microarray and validated by qPCR and in situ hybridization analyses. Taken together, our data support the hypothesis that the peripheral nerve regeneration processes may be regulated by miRNA pathway. PMID:21689732

  16. Platelet-rich plasma gel in combination with Schwann cells for repair of sciatic nerve injury.

    PubMed

    Ye, Fagang; Li, Haiyan; Qiao, Guangxi; Chen, Feng; Tao, Hao; Ji, Aiyu; Hu, Yanling

    2012-10-15

    Bone marrow mesenchymal stem cells were isolated from New Zealand white rabbits, culture-expanded and differentiated into Schwann cell-like cells. Autologous platelet-rich plasma and Schwann cell-like cells were mixed in suspension at a density of 1 × 10(6) cells/mL, prior to introduction into a poly (lactic-co-glycolic acid) conduit. Fabricated tissue-engineered nerves were implanted into rabbits to bridge 10 mm sciatic nerve defects (platelet-rich plasma group). Controls were established using fibrin as the seeding matrix for Schwann cell-like cells at identical density to construct tissue-engineered nerves (fibrin group). Twelve weeks after implantation, toluidine blue staining and scanning electron microscopy were used to demonstrate an increase in the number of regenerating nerve fibers and thickness of the myelin sheath in the platelet-rich plasma group compared with the fibrin group. Fluoro-gold retrograde labeling revealed that the number of Fluoro-gold-positive neurons in the dorsal root ganglion and the spinal cord anterior horn was greater in the platelet-rich plasma group than in the fibrin group. Electrophysiological examination confirmed that compound muscle action potential and nerve conduction velocity were superior in the platelet-rich plasma group compared with the fibrin group. These results indicate that autologous platelet-rich plasma gel can effectively serve as a seeding matrix for Schwann cell-like cells to construct tissue-engineered nerves to promote peripheral nerve regeneration. PMID:25538751

  17. Optic Nerve Monitoring

    PubMed Central

    Schumann, Paul; Kokemüller, Horst; Tavassol, Frank; Lindhorst, Daniel; Lemound, Juliana; Essig, Harald; Rücker, Martin; Gellrich, Nils-Claudius

    2013-01-01

    Orbital and anterior skull base surgery is generally performed close to the prechiasmatic visual pathway, and clear strategies for detecting and handling visual pathway damage are essential. To overcome the common problem of a missed clinical examination because of an uncooperative or unresponsive patient, flash visual evoked potentials and electroretinograms should be used. These electrophysiologic examination techniques can provide evidence of intact, pathologic, or absent conductivity of the visual pathway when clinical assessment is not feasible. Visual evoked potentials and electroretinograms are thus essential diagnostic procedures not only for primary diagnosis but also for intraoperative evaluation. A decision for or against treatment of a visual pathway injury has to be made as fast as possible due to the enormous importance of the time elapsed with such injuries; this can be achieved additionally using multislice spiral computed tomography. The first-line conservative treatment of choice for such injuries is megadose methylprednisolone therapy. Surgery is used to decompress the orbital compartment by exposure of the intracanalicular part of the optic nerve in the case of optic canal compression. Modern craniomaxillofacial surgery requires detailed consideration of the diagnosis and treatment of traumatic visual pathway damage with the ultimate goal of preserving visual acuity. PMID:24436741

  18. Critical displacement for unlimited displacement of earthquake-induced landslides

    NASA Astrophysics Data System (ADS)

    Fukuoka, H.; Karnawati, D.; Dok, A.

    2012-04-01

    The 30 September 2009 Padang Earthquake not only affected the buildings and infrastructure of the city, but also induced numerous landslides in the remote hill slopes. (1) A lot of shallow landslides took place along the southern crater rim of the lake Singkarak. Some of them were fluidized and ran as debris flows. (2) In a small town, located south of the lake, several large scale and long run-out landslides took place on hill slopes of pumiceous materials and claimed as many casualties. Those sands were sampled in a landslide deposits and tested by undrained ring shear apparatus by applying cyclic loading with corresponding static normal stress and shear stress. We found that about 5 cm could be the critical shear displacement when the shear resistance get smaller than shear stress due to excess pore pressure generation and thereafter unlimited displacement would appear. The critical displacement may depends on the saturation degree, static stresses acting on the slope, material, density, etc.

  19. Locating the target nerve and injectate spread in rabbit sciatic nerve block

    Microsoft Academic Search

    Duk Hyun Sung

    2004-01-01

    Background and objectivesThe purpose of this study is to determine how close the needle tip is placed to the target nerve using a nerve stimulator and to determine how far the injectate spreads in percutaneous nerve blocks.

  20. Alveolar nerve unfolding technique for synoptic analysis: visualization and quantification of inferior alveolar nerve tracings in three-dimensional cone-beam computed tomography.

    PubMed

    Jacquet, Wolfgang; Nyssen, Edgard; Sun, Yi; De Munter, Stephanie; Sijbers, Jan; Politis, Constantinus

    2013-07-01

    The aim of the technique presented here is to visualize the anatomical context of the inferior alveolar nerve (IAN) canal. For 2 cases, cone-beam computed tomography images of the mandible were obtained from patient files together with the manual preoperative IAN canal tracings. For both cases, similar to simulated panoramic images, a two-dimensional image is extracted from a three-dimensional cone-beam computed tomography image. Unlike panoramic images, the unfolding does not follow the general curvature of the mandible but follows the nerve tracing closely and places the traced nerve track on a horizontal central line. Because of the centering of the nerve tracing together with the nerve canal and its surroundings in a two-dimensional representation, the technique (ANUTSA [Alveolar Nerve Unfolding Technique for Synoptic Analysis]) allowed the first case to evidence the adjacency of root tips along the IAN, whereas in the second case the degree of penetration of the IAN by an implant is revealed. The global aspect of the representation through unfolding allowed for the detection of the anomalies and the IAN-penetrating lesion along the IAN canal at a glance. PMID:23851874

  1. The behavior of neuronal cells on tendon-derived collagen sheets as potential substrates for nerve regeneration.

    PubMed

    Alberti, Kyle A; Hopkins, Amy M; Tang-Schomer, Min D; Kaplan, David L; Xu, Qiaobing

    2014-04-01

    Peripheral nervous system injuries result in a decreased quality of life, and generally require surgical intervention for repair. Currently, the gold standard of nerve autografting, based on the use of host tissue such as sensory nerves is suboptimal as it results in donor-site loss of function and requires a secondary surgery. Nerve guidance conduits fabricated from natural polymers such as collagen are a common alternative to bridge nerve defects. In the present work, tendon sections derived through a process named bioskiving were studied for their potential for use as a substrate to fabricate nerve guidance conduits. We show that cells such as rat Schwann cells adhere, proliferate, and align along the fibrous tendon substrate which has been shown to result in a more mature phenotype. Additionally we demonstrate that chick dorsal root ganglia explants cultured on the tendon grow to similar lengths compared to dorsal root ganglia cultured on collagen gels, but also grow in a more oriented manner on the tendon sections. These results show that tendon sections produced through bioskiving can support directional nerve growth and may be of use as a substrate for the fabrication of nerve guidance conduits. PMID:24461939

  2. The Behavior of Neuronal Cells on Tendon-Derived Collagen Sheets as Potential Substrates for Nerve Regeneration

    PubMed Central

    Alberti, Kyle; Hopkins, Amy; Tang-Schomer, Min; Kaplan, David L.; Xu, Qiaobing

    2014-01-01

    Peripheral nervous system injuries result in a decreased quality of life, and generally require surgical intervention for repair. Currently, the gold standard of nerve autografting, based on the use of host tissue such as sensory nerves is suboptimal as it results in donor-site loss of function and requires a secondary surgery. Nerve guidance conduits fabricated from natural polymers such as collagen are a common alternative to bridge nerve defects. In the present work, tendon sections derived through a process named bioskiving were studied for their potential for use as a substrate to fabricate nerve guidance conduits. We show that cells such as rat Schwann cells adhere, proliferate, and align along the fibrous tendon substrate which has been shown to result in a more mature phenotype. Additionally we demonstrate that chick dorsal root ganglia explants cultured on the tendon grow to similar lengths compared to dorsal root ganglia cultured on collagen gels, but also grow in a more oriented manner on the tendon sections. These results show that tendon sections produced through bioskiving can support directional nerve growth and may be of use as a substrate for the fabrication of nerve guidance conduits. PMID:24461939

  3. Displacement rank of the Drazin inverse

    NASA Astrophysics Data System (ADS)

    Diao, Huaian; Wei, Yimin; Qiao, Sanzheng

    2004-05-01

    In this paper, we study the displacement rank of the Drazin inverse. Both Sylvester displacement and the generalized displacement are discussed. We present upper bounds for the ranks of the displacements of the Drazin inverse. The general results are applied to the group inverse of a structured matrix such as close-to-Toeplitz, generalized Cauchy, Toeplitz-plus-Hankel, and Bezoutians.

  4. Dual pressure displacement control system

    SciTech Connect

    Louis, J.E.; Klocke, C.C.

    1988-02-02

    This patent describes a dual pressure servo control system for a variable displacement hydraulic unit having displacement setting means positioned by a hydraulic servo mechanism. The hydraulic unit is provided with main loop lines at least one of which is capable of being subjected to high main loop pressure during operation of the hydraulic unit, a control line including a displacement control valve providing a controlled flow of fluid under pressure to the servo mechanism, and a source of fluid under pressure for the control line comprising a low pressure source connected to the control line through a check valve and high pressure source comprising of a high pressure control line connected to the control line downstream of the check valve. The high pressure control line includes a flow restriction limiting flow to the control line means and generating a significant flow induced pressure drop in the high pressure control line once movement in the servo mechanism is initiated.

  5. Gravitropic curvature of maize roots is not preceded by rootcap asymmetry

    NASA Technical Reports Server (NTRS)

    Sack, F. D.; Hasenstein, K. H.; Blair, A.

    1990-01-01

    We tested whether the first response to gravistimulation is an asymmetry in the root tip that results from differential growth of the rootcap itself. The displacement of markers on the rootcap surface of maize (Zea mays L. cv. Merit) roots was quantified from videotaped images using customized software. The method was sensitive enough to detect marker displacements down to 15 microns and root curvature as early as 8 min after gravistimulation. No differential growth of the upper and lower sides of the cap occurred before or during root curvature. Fewer than a third of all gravistimulated roots developed an asymmetrical outline of the root tip after curvature had started, and this asymmetry did not occur in the rootcap itself. Our data support the view that the regions of gravitropic sensing and curvature are spatially separate during all phases of gravitropism in maize roots.

  6. Cervical dermatomal zona misdiagnosed as ulnar nerve entrapment.

    PubMed

    ?alçini, Celal; Sunter, Gülin; Gumustas, Seyit Ali; Evrensel, Alper

    2015-01-01

    Herpes zoster is a secondary reactivation of primary contagious varicella-zoster virus in the dorsal root ganglia. While thoracic zona is common, cervical dermatomal zona is a rare segmental complication of herpes zoster and can be easily misdiagnosed as other diseases. This article describes a patient with initial neuralgia without dermatomal lesions that was treated as ulnar nerve entrapment syndrome until manifestation of herpetiform cutaneous lesions appeared. It is important that clinicians should be aware of the possibility of zoster infection when evaluating the onset of neuralgia in a dermatomal distribution in the upper limb, especially without rash. PMID:26032704

  7. Particle displacement tracking for PIV

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  8. Rotor component displacement measurement system

    DOEpatents

    Mercer, Gary D.; Li, Ming C.; Baum, Charles R.

    2003-05-27

    A measuring system for measuring axial displacement of a tube relative to an axially stationary component in a rotating rotor assembly includes at least one displacement sensor adapted to be located normal to a longitudinal axis of the tube; an insulated cable system adapted for passage through the rotor assembly; a rotatable proximitor module located axially beyond the rotor assembly to which the cables are connected; and a telemetry system operatively connected to the proximitor module for sampling signals from the proximitor module and forwarding data to a ground station.

  9. Assessment of nerve involvement in the lumbar spine: agreement between magnetic resonance imaging, physical examination and pain drawing findings

    PubMed Central

    2010-01-01

    Background Detection of nerve involvement originating in the spine is a primary concern in the assessment of spine symptoms. Magnetic resonance imaging (MRI) has become the diagnostic method of choice for this detection. However, the agreement between MRI and other diagnostic methods for detecting nerve involvement has not been fully evaluated. The aim of this diagnostic study was to evaluate the agreement between nerve involvement visible in MRI and findings of nerve involvement detected in a structured physical examination and a simplified pain drawing. Methods Sixty-one consecutive patients referred for MRI of the lumbar spine were - without knowledge of MRI findings - assessed for nerve involvement with a simplified pain drawing and a structured physical examination. Agreement between findings was calculated as overall agreement, the p value for McNemar's exact test, specificity, sensitivity, and positive and negative predictive values. Results MRI-visible nerve involvement was significantly less common than, and showed weak agreement with, physical examination and pain drawing findings of nerve involvement in corresponding body segments. In spine segment L4-5, where most findings of nerve involvement were detected, the mean sensitivity of MRI-visible nerve involvement to a positive neurological test in the physical examination ranged from 16-37%. The mean specificity of MRI-visible nerve involvement in the same segment ranged from 61-77%. Positive and negative predictive values of MRI-visible nerve involvement in segment L4-5 ranged from 22-78% and 28-56% respectively. Conclusion In patients with long-standing nerve root symptoms referred for lumbar MRI, MRI-visible nerve involvement significantly underestimates the presence of nerve involvement detected by a physical examination and a pain drawing. A structured physical examination and a simplified pain drawing may reveal that many patients with "MRI-invisible" lumbar symptoms need treatment aimed at nerve involvement. Factors other than present MRI-visible nerve involvement may be responsible for findings of nerve involvement in the physical examination and the pain drawing. PMID:20831785

  10. The movement of a nerve in a magnetic field: application to MRI Lorentz effect imaging.

    PubMed

    Roth, Bradley J; Luterek, Adam; Puwal, Steffan

    2014-05-01

    Direct detection of neural activity with MRI would be a breakthrough innovation in brain imaging. A Lorentz force method has been proposed to image nerve activity using MRI; a force between the action currents and the static MRI magnetic field causes the nerve to move. In the presence of a magnetic field gradient, this will cause the spins to precess at a different frequency, affecting the MRI signal. Previous mathematical modeling suggests that this effect is too small to explain the experimental data, but that model was limited because the action currents were assumed to be independent of position along the nerve and because the magnetic field was assumed to be perpendicular to the nerve. In this paper, we calculate the nerve displacement analytically without these two assumptions. Using realistic parameter values, the nerve motion is <5 nm, which induced a phase shift in the MRI signal of <0.02°. Therefore, our results suggest that Lorentz force imaging is beyond the capabilities of current technology. PMID:24728667

  11. The Movement of a Nerve in a Magnetic Field: Application to MRI Lorentz Effect Imaging

    PubMed Central

    Roth, Bradley J.; Luterek, Adam; Puwal, Steffan

    2014-01-01

    Direct detection of neural activity with MRI would be a breakthrough innovation in brain imaging. A Lorentz force method has been proposed to image nerve activity using MRI; a force between the action currents and the static MRI magnetic field causes the nerve to move. In the presence of a magnetic field gradient, this will cause the spins to precess at a different frequency, affecting the MRI signal. Previous mathematical modeling suggests that this effect is too small to explain the experimental data, but that model was limited because the action currents were assumed to be independent of position along the nerve, and because the magnetic field was assumed to be perpendicular to the nerve. In this paper, we calculate the nerve displacement analytically without these two assumptions. Using realistic parameter values, the nerve motion is less than 5 nm, which induced a phase shift in the MRI signal of less than 0.02°. Therefore, our results suggest that Lorentz force imaging is beyond the capabilities of current technology. PMID:24728667

  12. Cranial nerve assessment in posterior fossa tumors with fast imaging employing steady-state acquisition (FIESTA).

    PubMed

    Mikami, Takeshi; Minamida, Yoshihiro; Yamaki, Toshiaki; Koyanagi, Izumi; Nonaka, Tadashi; Houkin, Kiyohiro

    2005-10-01

    Steady-state free precession is widely used for ultra-fast cardiac or abdominal imaging. The purpose of this work was to assess fast imaging employing steady-state acquisition (FIESTA) and to evaluate its efficacy for depiction of the cranial nerve affected by the tumor. Twenty-three consecutive patients with posterior fossa tumors underwent FIESTA sequence after contrast agent administration, and then displacement of the cranial nerve was evaluated. The 23 patients with posterior fossa tumor consisted of 12 schwannomas, eight meningiomas, and three cases of epidermoid. Except in the cases of epidermoid, intensity of all tumors increased on FIESTA imaging of the contrast enhancement. In the schwannoma cases, visualization of the nerve became poorer as the tumor increased in size. In cases of encapsulated meningioma, all the cranial nerves of the posterior fossa were depicted regardless of location. The ability to depict the nerves was also significantly higher in meningioma patients than in schwannoma patients (P<0.05). In cases of epidermoid, extension of the tumors was depicted clearly. Although the FIESTA sequence offers similar contrast to other heavily T2-weighted sequences, it facilitated a superior assessment of the effect of tumors on cranial nerve anatomy. FIESTA sequence was useful for preoperative simulations of posterior fossa tumors. PMID:15933875

  13. Facial-hypoglossal nerve anastomosis using laser nerve welding.

    PubMed

    Hwang, Kun; Kim, Sun Goo; Kim, Dae Joong

    2006-07-01

    The aim of this study is to compare laser nerve welding to microsurgical suturing of hypoglossal-facial nerve anastomosis (HFA), and a result of immediate to delayed repair, and to evaluate the effect of laser nerve welding on HFA for reanimation of facial palsy. The first group of five rats underwent immediate HFA by microsurgical suturing and the second group of five rats by CO2 laser welding. The third group of five rats underwent delayed HFA by microsurgical suturing, and the fourth group of five rats by laser nerve welding. The fifth group of five rats served as controls, with intact hypoglossal and facial nerve. In all rats of the four different treatment groups, cholera toxin B subunit (CTb) was injected in the epineurium distal to the anastomosis site on the postoperative 6th week and in the normal hypoglossal nerve in the five rats of the control group. Neurons labeled CTb of hypoglossal nuclei were positive immunohistochemically, and the numbers were counted. In the immediate HFA groups, CTb-positive neurons were 751 +/- 247 in the laser welding group (n = 5) and 888 +/- 60 in the microsurgical suturing group (n = 5). There was no significant difference (P = 0.117). In the delayed HFA groups, CTb-positive neurons were 749 +/- 54 in the laser welding group (n = 5) and 590 +/- 169 in the microsurgical suturing group (n = 5). The difference was not significant (P = 0.116). There was no significant difference between immediate and delayed anastomosis in the laser welding group (P = 0.600), but there was significance between immediate and delayed anastomosis in the microsurgical suturing group (P = 0.009). Injected CTb in intact hypoglossal neurons (n = 5) were labeled 1,003 +/- 52. No dehiscence in the laser welding site of nerve anastomosis was seen at the time of re-exploration for injection of CTb in all 10 rats. This study shows that the regeneration of anastomosed hypoglossal-facial nerve was affected similarly by laser welding and microsurgical suturing, and more effective, especially in delayed repair. PMID:16877915

  14. Interleukin-10 levels in rat models of nerve damage and neuropathic pain.

    PubMed

    Khan, Junad; Ramadan, Khaled; Korczeniewska, Olga; Anwer, Muhammad Moin; Benoliel, Rafael; Eliav, Eli

    2015-04-10

    Interleukin-10 (IL-10) is an anti-inflammatory cytokine that has been shown to play a role in inflammatory and autoimmune disorders as well as in neuropathic pain conditions. The objective of the present study was to assess the levels of IL-10 in rat's dorsal root ganglion (DRG) and the sciatic nerve following four different forms of sciatic nerve injury. The models used to induce the injury included two models of partial nerve injury: partial sciatic ligation (PSL) and chronic constriction injury (CCI), a model of complete sciatic transection (CST) and a model of perineural inflammation with minimal nerve damage (neuritis). Withdrawal responses for mechanical stimulus and withdrawal latency for thermal stimulation were used to measure mechanical and thermal hyperalgesia, respectively, and duration of the nociceptive withdrawal reflex to mechanical stimulus was used to measure mechanical hyperalgesia. The affected and contra-lateral nerves and the affected side DRG IL-10 levels were assessed by the means of enzyme-linked immunosorbent assay (ELISA), 3 and 8 days following the procedure and were compared to naïve rats' IL-10 levels. The rats exposed to CCI and neuritis developed significant mechanical and thermal hyperalgesia as well as mechanical hyperalgesia 3 and 8 days following the surgical procedure. Rats exposed to CST did not respond to mechanical stimulation and developed thermal hypoalgesia 3 and 8 days after the surgery. The DRG IL-10 levels were significantly reduced 3 and 8 days following CCI and PSL, significantly increased 3 and 8 days following CST, and remained unchanged following neuritis. The sciatic nerve IL-10 levels reduced significantly in both injured and contra-lateral nerves 3 and 8 days following CCI and PSL, elevated significantly in the injured but not in the contra-lateral nerve 3 and 8 days following CST and remained unchanged following neuritis. The results of this study suggest that IL-10's role in the neuropathic pain etiology may be specific to nerve injury type. Complete nerve transection increases while partial nerve injury reduces IL-10 levels in the involved nerve, and DRG. Perineural inflammation with minimal nerve damage has no effect on IL-10 levels. PMID:25757362

  15. Assessing building displacement with GPS

    Microsoft Academic Search

    Andrés Seco; Fermín Tirapu; Francisco Ramírez; Beñat García; Jesús Cabrejas

    2007-01-01

    In the frame of its researches concerning GPS positioning the Universidad Pública de Navarra has carried out in 2003 a study to know the possibilities of this positioning technique for monitoring building's displacements. A 30m concrete building was monitored for several months by observations from a geodetic micronetwork placed around.During the observation period the computed variations in position have standard

  16. DISPLACEMENT BASED SEISMIC DESIGN METHODS.

    SciTech Connect

    HOFMAYER,C.MILLER,C.WANG,Y.COSTELLO,J.

    2003-07-15

    A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREGICR-6719 in July 2001, is presented in this paper.

  17. Laboratory displacement with micellar solutions

    Microsoft Academic Search

    1967-01-01

    Slugs of micellar solutions, displaced by thickened water, were evaluated in Berea sandstone cores, previously waterflooded to residual oil saturation. The performance and flow behavior of one of these slugs is described. Flooding performance is remarkable: A 1% pore volume slug recovered 59% of the tertiary oil-in-place, while a 5% pore volume slug recovered 100% of the crude oil from

  18. Pulsed Radiofrequency of Lumbar Dorsal Root Ganglion for Chronic Postamputation Phantom Pain

    PubMed Central

    Imani, Farnad; Gharaei, Helen; Rezvani, Mehran

    2012-01-01

    Chronic pain following lower-limb amputation is now a well-known neuropathic, chronic-pain syndrome that usually presents as a combination of phantom and stump pain. Controlling these types of neuropathic pain is always complicated and challenging. If pharmacotherapy does not control the patient’s pain, interventional procedures have to be taken. The aim of this study was to evaluate the efficacy of using pulsed radiofrequency (PRF) on the dorsal root ganglia at the L4 and L5 nerve roots to improve phantom pain. Two patients with phantom pain were selected for the study. After a positive response to segmental nerve blockade at the L4 and L5 nerve roots, PRF was performed on the L4 and L5 dorsal root ganglia. Global clinical improvement was good in one patient, with a 40% decrease in pain on the visual analogue scale (VAS) in 6 months, and moderate in the second patient, with a 30% decrease in pain scores in 4 months. PRF of the dorsal root ganglia at the L4 and L5 nerve roots may be an effective therapeutic option for patients with refractory phantom pain. PMID:24904793

  19. Nerve blocks in palliative care.

    PubMed

    Chambers, W A

    2008-07-01

    Although between 85% and 90% of patients with advanced cancer can have their pain well controlled with the use of analgesic drugs and adjuvants, there are some patients who will benefit from an interventional procedure. This includes a variety of nerve blocks and also some neurosurgical procedures. Approximately 8-10% of patients may benefit from a peripheral nerve block and around 2% from a central neuraxial block. The most common indication is because opioid dose escalation is limited by signs of opioid toxicity but some patients will benefit from one component of their pain being relieved by a simple peripheral block. Most patients about to undergo these procedures are already taking high doses of opiods and obtaining valid consent may pose problems. The use of peripheral nerve blocks, epidural and intrathecal infusions, and plexus blocks is discussed. PMID:18495677

  20. Neuromodulation of the suprascapular nerve.

    PubMed

    Elahi, Foad; Reddy, Chandan G

    2014-01-01

    The shoulder joint is an enarthrodial or ball-and-socket joint. A complex network of anatomic structures endows the human shoulder with tremendous mobility, greater than any other joint in the body. Many pathologies can been found in those patients with chronic shoulder pain. The painful limitation of shoulder motion affects hand and arm motion as well; therefore, it significantly influences work performance and everyday activities as well as the quality of life. Therefore, the treatment of patients with chronic shoulder pain has major social and health economic implications. In this article we present a patient with a complex history of shoulder pathology including 7 surgeries that left the patient with chronic debilitating shoulder pain. She was suffering from chronic pain and limited mobility of the shoulder joint due to adhesive shoulder capsulitis. She was treated with a multimodality approach with the goals of increasing shoulder range of motion and decreasing her pain. This did not provide significant improvement. The suprascapular nerve supplies motor and sensory innervation to the shoulder, and can be easily accessible in the supraspinatus fossa. A suprascapular nerve block dramatically decreased her pain. This clinical observation along with confirmatory nerve block play an important role during the decision-making process for a trial period of electrical neuromodulation. She was followed for 3 months after the permanent implantation of a suprascapular nerve stimulator. Her pain and shoulder range of motion in all planes improved dramatically. Peripheral nerve stimulation (PNS) of the suprascapular nerve, in addition to multimodality pain management, is one approach to the difficult task of treating adhesive capsulitis with accompanying pain and the inability to move the shoulder. We conducted a literature review on PubMed and found no case describing a similar patient to our knowledge. PMID:25415792

  1. Genetic knockout and pharmacologic inhibition of neuronal nitric oxide synthase attenuate nerve injury-induced mechanical hypersensitivity in mice

    PubMed Central

    Guan, Yun; Yaster, Myron; Raja, Srinivasa N; Tao, Yuan-Xiang

    2007-01-01

    Neuronal nitric oxide synthase (nNOS) is a key enzyme for nitric oxide production in neuronal tissues and contributes to the spinal central sensitization in inflammatory pain. However, the role of nNOS in neuropathic pain remains unclear. The present study combined a genetic strategy with a pharmacologic approach to examine the effects of genetic knockout and pharmacologic inhibition of nNOS on neuropathic pain induced by unilateral fifth lumbar spinal nerve injury in mice. In contrast to wildtype mice, nNOS knockout mice failed to display nerve injury-induced mechanical hypersensitivity. Furthermore, either intraperitoneal (100 mg/kg) or intrathecal (30 ?g/5 ?l) administration of L-NG-nitro-arginine methyl ester, a nonspecific NOS inhibitor, significantly reversed nerve injury-induced mechanical hypersensitivity on day 7 post-nerve injury in wildtype mice. Intrathecal injection of 7-nitroindazole (8.15 ?g/5 ?l), a selective nNOS inhibitor, also dramatically attenuated nerve injury-induced mechanical hypersensitivity. Western blot analysis showed that the expression of nNOS protein was significantly increased in ipsilateral L5 dorsal root ganglion but not in ipsilateral L5 lumbar spinal cord on day 7 post-nerve injury. The expression of inducible NOS and endothelial NOS proteins was not markedly altered after nerve injury in either the dorsal root ganglion or spinal cord. Our findings suggest that nNOS, especially in the dorsal root ganglion, may participate in the development and/or maintenance of mechanical hypersensitivity after nerve injury. PMID:17922909

  2. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  3. Design, fabrication and evaluation of a conforming circumpolar peripheral nerve cuff electrode for acute experimental use

    PubMed Central

    Foldes, Emily L.; Ackermann, D. Michael; Bhadra, Niloy; Kilgore, Kevin L.; Bhadra, Narendra

    2011-01-01

    Nerve cuff electrodes are a principle tool of basic and applied electro-neurophysiology studies and are championed for their ability to achieve good nerve recruitment with low thresholds. We describe the design and method of fabrication for a novel circumpolar peripheral nerve electrode for acute experimental use. This cylindrical cuff-style electrode provides approximately 270 degrees of radial electrode contact with a nerve for each of an arbitrary number of contacts, has a profile that allows for simple placement and removal in an acute nerve preparation, and is designed for adjustment of the cylindrical diameter to ensure a close fit on the nerve. For each electrode, the electrical contacts were cut from 25 µm platinum foil as an array so as to maintain their positions relative to each other within the cuff. Lead wires were welded to each intended contact. The structure was then molded in silicone elastomer, after which the individual contacts were electrically isolated. The final electrode was curved into a cylindrical shape with an inner diameter corresponding to that of the intended target nerve. The positions of these contacts were well maintained during the molding and shaping process and failure rates during fabrication due to contact displacements were very low. Established electrochemical measurements were made on one electrode to confirm expected behavior for a platinum electrode and to measure the electrode impedance to applied voltages at different frequencies. These electrodes have been successfully used for nerve stimulation, recording, and conduction block in a number of different acute animal experiments by several investigators. PMID:21187115

  4. Concomitant abducens and facial nerve palsies following blunt head trauma associated with bone fracture.

    PubMed

    Ji, Min-Jeong; Han, Sang-Beom; Lee, Seung-Jun; Kim, Moosang

    2015-01-01

    A 22-year-old man was referred for horizontal diplopia that worsened on left gaze. He had been admitted for a head trauma caused by a traffic accident. Brain CT scan showed a longitudinal fracture of the left temporal bone with extension to the left carotid canal and central skull base, including sphenoid lateral wall and roof, and left orbit medial wall non-displaced fracture. Prism cover test revealed 20 prism diopters of esotropia and abduction limitation in the left eye. Hess screening test results were compatible with left abducens nerve paralysis. Symptoms suggesting complete lower motor neuron palsy of the left facial nerve, such as unilateral facial drooping, inability to raise the eyebrow and difficulty closing the eye, were present. As there was no improvement in facial paralysis, the patient received surgical intervention using a transmastoidal approach. Three months postoperatively, prism cover test showed orthotropia, however, the facial nerve palsy persisted. PMID:26178005

  5. [Ultrasound-guided sciatic nerve block].

    PubMed

    Ota, Junichi; Hara, Kaoru

    2008-05-01

    Theoretically, sciatic nerve block can be used alone or in combination with lumbar plexus block or femoral nerve block for anesthesia and/or analgesia of lower limb surgery. However, clinical use of sciatic nerve block was limited by technical difficulties in performing the block since techniques used relies only on surface anatomical landmarks. Recent advances in ultrasound technology allow direct visualization of nerves and other surrounding structures and have increased the interest in performing many kinds of peripheral nerve blocks including sciatic nerve block. Preliminary data suggest that ultrasound-guided technique can help perform the sciatic nerve block more reliably and safely. In this article we describe the anatomy of the sciatic nerve, sonographic features, and technique of three major approaches including subgluteal, anterior, and popliteal approaches. The use of this technique for postoperative analgesia is also discussed. PMID:18516885

  6. Electromagnetic mechanism of magnetic nerve stimulation

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Masuhiro; Yamada, Satoshi; Daimon, Nobuo; Yamamoto, Isao; Kawakami, Tadashi; Takenaka, Toshibumi

    1989-08-01

    Rabbit sciatic nerves were stimulated by pulsed magnetic fields and nerve responses were analyzed on the basis of electromagnetic theory to understand the dominant factors in magnetic stimulation. Some conducting substance surrounding the nerve is required to induce the currents exciting it. The strength of a magnetic stimulus is evaluated by the rate of change in the vector potential at the nerve, dA/dt, which equals the magnitude of the induced electric field E. The minimum strength of dA/dt for exciting the nerve is 18 Wb/ms (18 V/m) in the agar with a conductivity of 0.6 S/m. The induced current density of 10 A/m2 is comparable to that used in the electric stimulation of peripheral nerves. The component of the vector potential parallel to the nerve is more effective in stimulating the nerve than the component perpendicular to it.

  7. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  8. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  9. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  10. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  11. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors). (b) Classification. Class II (performance...

  12. Crustal displacements due to continental water loading

    USGS Publications Warehouse

    Van Dam, T.; Wahr, J.; Milly, P.C.D.; Shmakin, A.B.; Blewitt, G.; Lavallee, D.; Larson, K.M.

    2001-01-01

    The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (??rM) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm, with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare ??rM with observed Global Positioning System (GPS) heights (??rO) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the ??rO time series are adjusted by ??rM, their variances are reduced, on average, by an amount equal to the variance of the ??rM. Of the ??rO time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the ??rM. The ??rM time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.

  13. Free displacer and Ringbom displacer for a Malone refrigerator

    SciTech Connect

    Swift, G.W.; Brown, A.O.

    1994-05-01

    Malone refrigeration uses a liquid near its critical point (instead of the customary gas) as the working fluid in a Stirling, Brayton, or similar regenerative or recuperative cycle. Thus far, we have focused on the Stirling cycle, to avoid the difficult construction of the high-pressure-difference counterflow recuperator required for a Brayton machine. Our first Malone refrigerator used liquid propylene (C{sub 3}H{sub 6}) in a double-acting 4-cylinder Stirling configuration. First measurements with a free displacer used in a liquid working fluid are presented. The displacer was operated both in harmonic mode and in Ringbom mode, in liquid carbon dioxide. The results are in reasonable agreement with expectations.

  14. Voluntary Nerve Signals from Severed Mammalian Nerves: Long-Term Recordings

    E-print Network

    De Luca, Carlo J.

    and peroneal nerves in rabbits. This electrode may prove suitable for implantation in human amputeesVoluntary Nerve Signals from Severed Mammalian Nerves: Long-Term Recordings Abstract. An electrode unit capable ofdetecting voluntarily elicited nerve signals for prolonged periods oftime has been

  15. Microsurgical anatomy of the ocular motor nerves

    Microsoft Academic Search

    Yi ZhangHao; Hao Liu; En-Zhong Liu; You-Zhi Lin; Shi-Guang Zhao; Guo-Hua Jing

    2010-01-01

    This study was designed to provide anatomic data to help surgeons avoid damage to the ocular motor nerves during intraorbital\\u000a operations. The microsurgical anatomy of the ocular motor nerves was studied in 50 adult cadaveric heads (100 orbits). Dissections\\u000a were performed with a microscope. The nerves were exposed and the neural and muscular relationships of each portion of the\\u000a nerve

  16. The spinal cord ventral root: an afferent pathway of the hind-limb pressor reflex in cats.

    PubMed Central

    Longhurst, J C; Mitchell, J H; Moore, M B

    1980-01-01

    1. In anaesthetized cats the sciatic nerve was cut and the central end was stimulated at a high frequency and voltage. This caused an increase in arterial blood pressure and a rise in heart rate. The pressure response was diminished by dorsal root section but not completely eliminated until ventral root section (L4-S3). The tachycardia response was abolished by dorsal root section alone. 2. In other cats capsaicin was injected intra-arterially into the hind limb, causing elevations in both blood pressure and heart rate. Similar to the sciatic nerve stimulation experiments, the pressor response was principally reduced by dorsal root section but was further significantly decreased by ventral root section (L1-S3). The rise in heart rate was prevented by dorsal root section alone. 3. It is concluded that, in cats, the afferent pathway of the pressor response to sciatic nerve stimulation and to hind-limb capsaicin injection are conducted principally in the dorsal roots but also to a small extent in the ventral roots of the spinal cord. Although the tachycardia response appears to be conducted only through the dorsal roots, it is possible that at lower resting heart rates and by stimulation of a large population of the unmyelinated skeletal muscle afferents, the ventral root is a functional pathway. PMID:7411444

  17. Continuous Retrograde Monitoring of the Facial Nerve During Cerebellopontine Angle Surgery

    PubMed Central

    Colletti, Vittorio; Fiorino, Francesco

    1996-01-01

    An alternative technique for the continuous monitoring of the facial nerve, monopolar recording of facial nerve antidromic potentials (FNAPs), on 10 subjects undergoing retrosigmoid vestibular neurectomy for Meniere's disease is described. To elicit FNAPs bipolar electrical stimulation of the marginalis mandibulae was performed. Stimulus intensity ranged from 0 to 10 mA with a delivery rate of 7/second. Antidromic potentials were recorded with a silver wire monopolar electrode positioned intracranially on the proximal portion (root entry zone) of the acoustic-facial bundle. Bipolar recordings with two silver electrodes were also performed from different nerves in the cerebellopontine angle to define the specific origin of the action potentials. FNAP. amplitude increased as a function of stimulus intensity. The average latency was 3.35 milliseconds (range 3.0 to 3.7 ms). Action potentials recorded intracranially during electrical stimulation of the marginal nerve originated specifically from the facial nerve. FNAP recording is therefore a promising technique for the continuous intraoperative monitoring of the facial nerve during cerebellopontine angle surgery. PMID:17170952

  18. Cranial Nerves Model - PowerPoint Presentation

    NSDL National Science Digital Library

    Juliann Garza (University of Texas-Pan American Physician Assistant Studies)

    2010-08-16

    Lesson is designed to introduce students to cranial nerves through the use of an introductory lecture. Students will then create a three-dimensional model of the cranial nerves. An information sheet will accompany the model in order to help students learn crucial aspects of the cranial nerves.

  19. SELECTIVE STIMULATION OF THE HUMAN OPTIC NERVE

    Microsoft Academic Search

    C. Veraart; J. Delbeke; M.-C. Wanet-Defalque; A. Vanlierde; G. Michaux; S. Parrini; O. Glineur; M. Verleysen; C. Trullemans; J. T. Mortimer

    1999-01-01

    A blind volunteer affected with retinitis pigmentosa was intracranially implanted with a self- sizing cuff electrode around her right optic nerve. The nerve cuff electrode included 4 monopolar contacts. Its leads were brought through the skin where they ended in an external connector12. After recovery from surgery, electrical activation of the implanted optic nerve was undertaken. A specially dedicated Computer

  20. Action of Quaternary Ammonium Salts on Nerve

    Microsoft Academic Search

    S. L. Cowan

    1933-01-01

    EXPERIMENTS similar to those of Fromherz with curare on medullated nerve, referred to by Prof. A. V. Hill in his article on ``The Physical Nature of the Nerve Impulse'',1 in NATURE of April 8, have been made with pure quaternary ammonium salts prepared by Dr. H. R. Ing. These have a curare-like action, preventing transmission of excitation from nerve to

  1. Reinforcement of Tree Root and Non-frame Method in Slope Stabilization

    NASA Astrophysics Data System (ADS)

    Naoto, I.; Quang, N. Minh

    2009-04-01

    A root fiber can nail a slipping soil mass into the bedrock and thus can increase slope stability. The reinforcement of root fibers is considered as the resultant of tension and shear reinforces occurred in the cross section of root at slip surface. The shear force and bending moment of a deformed root directly prevent against the displacement of unstable soil mass while the tension force increase the friction force between unstable soil and bed rock. Longer displacement of slope causes larger deformation and thus causes larger reinforcement of tree root. In other side, larger root reinforcement results in more slope stability. The reinforcement of tree root and displacement of slipping soil mass depending on each other is the reinforcement mechanism of tree root in a landslide. The mechanism of tree root reinforcement is considered in developing a new soil nail method named Non-frame. By conducting a number of experiments of soil nail stabilizing slope, the alteration process of root reinforcement was performed in various conditions of rainfall and earthquake.

  2. Anatomical Variation: Median Nerve Formation – A Case Vignette

    PubMed Central

    Sinha, Pranoti; Tamang, Binod Kumar; Sarda, Rohit Kumar

    2014-01-01

    Variations in the arrangement and distribution of brachial plexus and its branches in the infraclavicular part are common and have been reported by several investigators since the 19th century. These variations are significant for the neurologists, surgeons, anesthetists and the anatomists. During routine anatomical dissection of the right axilla and infraclavicular region of a 45-year-old male cadaver, the medial root of the median nerve was found to receive a supplementary branch from the medial aspect of the terminal portion of the lateral cord of brachial plexus and the branch was passing infront of the axillary artery from lateral to medial side. The median nerve was formed by joining of the lateral and medial roots from the lateral and medial cords of brachial plexus, infront of brachial artery, lower down, at the junction of upper one-third and lower two-third of the arm, instead in the axilla. This variation could be one of the cause of pressure symptom which occurs on the axillary artery and also the injury which occurs on the lateral cord or upstream to the lateral cord, which may sometimes lead to an unexpected presentation of weakness of forearm flexors and thenar muscles. PMID:25120965

  3. Pathology of the optic nerves

    Microsoft Academic Search

    Y. Doron; A. Behar

    1968-01-01

    The optic nerves and chiasma were examined histologically in 124 unselected autopsy cases with clinical histories of arteriosclerotic cardiovascular disease (ASCVD), hypertensive cardiovascular disease (HCVD) and liver parenchymal damage (LPD) with a view to find out possible changes particularly associated with one of the three respective conditions. Statistical test applied to our material revealed, as was to be expected, a

  4. Polybenzimidazole via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor); Smith, Joseph G. (Inventor)

    1994-01-01

    Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-4-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

  5. Upscaling of Miscible Displacement Processes

    Microsoft Academic Search

    Dengen Zhou; Jairam Kamath; Lou Durlofsky; Erling H. Stenby

    In this paper, we present an approach for upscaling miscible displacement processes using a modified Todd-Longstaff (T-L) formulation. The T-L formulation is modified to include pseudo fractional flow curves. The pseudo fractional flow curves are calculated for each upscaled grid using the upscaling technique proposed by Christie et al.1 The new procedure is applied to a 2-D cross-section model. We

  6. Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

    PubMed Central

    Zhang, Yanru; Zhang, Hui; Katiella, Kaka; Huang, Wenhua

    2014-01-01

    A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group > chemically extracted acellular nerve graft + ciliary neurotrophic factor group > chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone. PMID:25221592

  7. Pharmacology of airway afferent nerve activity

    PubMed Central

    Undem, Bradley J; Carr, Michael J

    2001-01-01

    Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens) and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology. PMID:11686889

  8. Correlative ultrasound anatomy of the feline brachial plexus and major nerves of the thoracic limb.

    PubMed

    Ansón, Agustina; Gil, Francisco; Laredo, Francisco G; Soler, Marta; Belda, Eliseo; Ayala, Maria D; Agut, Amalia

    2013-01-01

    Brachial plexus avulsions commonly occur in cats due to traumatic injuries involving the shoulder. Ultrasound may be an effective method for detecting injured nerves. Additional applications may include characterization of brachial plexus neoplasms and guidance of anesthetic nerve blocks. Aims of this study were to describe ultrasonographic approaches and the normal appearance of this plexus and other major nerves of the thoracic limb in cats. Eight feline cadavers were used to determine anatomic landmarks, obtain cross-sectional anatomic images of the target nerves, and compare these with ultrasound images. An ultrasonographic study was performed in five fresh feline cadavers to assess the brachial plexus and its major components at the levels of the axilla and proximal, middle and distal (lateral and medial approaches) humeral regions. Five healthy adult cats were recruited for an in vivo ultrasonographic study using the same protocol described for the cadaver ultrasonographic study. The roots of the brachial plexus appeared as a cluster of small, round hypoechoic structures surrounded by a hyperechoic rim in the axillary approach. The radialis, medianus, and ulnaris nerves were individually visualized on proximal and middle humeral approaches. The medianus and ulnaris nerves were easily identified on the medial aspect of the humerus in the distal approach. The superficial branch of radialis nerve was seen on the lateral aspect of the distal humerus approach. The nerves appeared as oval-to-round hypoechogenic structures with a hyperechogenic rim. Future studies are needed to compare findings from this study with those in cats with confirmed brachial plexus injuries or other lesions. PMID:23363032

  9. Optimal optical measurement of small displacements

    Microsoft Academic Search

    Magnus T. L. Hsu; Vincent Delaubert; Ping Koy Lam; Warwick P. Bowen

    2004-01-01

    We derive the quantum noise limit for the optical beam displacement of a TEM00 mode. Using a multimodal analysis, we show that the conventional split detection scheme for measuring beam displacement is non-optimal with ~80% efficiency. We propose a new displacement measurement scheme that is optimal for small beam displacement. This scheme utilizes a homodyne detection set-up that has a

  10. Optimum Small Optical Beam Displacement Measurement

    Microsoft Academic Search

    Magnus T. L. Hsu; Vincent Delaubert; Ping Koy Lam; Warwick Bowen

    2004-01-01

    We derive the quantum noise limit for the optical beam displacement of a\\u000aTEM00 mode. Using a multimodal analysis, we show that the conventional split\\u000adetection scheme for measuring beam displacement is non-optimal with 80%\\u000aefficiency. We propose a new displacement measurement scheme that is optimal\\u000afor small beam displacement. This scheme utilises a homodyne detection setup\\u000athat has a

  11. Optimal optical measurement of small displacements

    Microsoft Academic Search

    Magnus T L Hsu; Vincent Delaubert; Ping Koy Lam; Warwick P Bowen

    2004-01-01

    We derive the quantum noise limit for the optical beam displacement of a TEM00 mode. Using a multimodal analysis, we show that the conventional split detection scheme for measuring beam displacement is non-optimal with ?80% efficiency. We propose a new displacement measurement scheme that is optimal for small beam displacement. This scheme utilizes a homodyne detection set-up that has a

  12. Displacement chromatography of isomers and therapeutic compounds

    Microsoft Academic Search

    Yan Qi; Junxiong Huang

    2002-01-01

    Displacement chromatography was successfully used to separate a binary isomer mixture, epirubicin and doxorubicin, on Kromasil KR100-10 C18 250×4.6 mm I.D. (10 ?m) column. Displacement parameters such as the types and the concentrations of displacer, the composition and the flow rate of the mobile phase were critically examined in this study. The displacer employed was 30 mg\\/ml benzethonium chloride. Loading

  13. Leptin-sensitive sensory nerves innervate white fat

    PubMed Central

    Murphy, Keegan T.; Schwartz, Gary J.; Nguyen, Ngoc Ly T.; Mendez, Jennifer M.; Ryu, Vitaly

    2013-01-01

    Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue. PMID:23612999

  14. Amniotic membrane covering for facial nerve repair?

    PubMed Central

    Karaman, Murat; Tuncel, Arzu; Sheidaei, Shahrouz; ?enol, Mehmet Güney; Karabulut, Murat Hakan; Deveci, Ildem; Karaman, Nihan

    2013-01-01

    Amniotic membranes have been widely used in ophthalmology and skin injury repair because of their anti-inflammatory properties. In this study, we measured therapeutic efficacy and determined if amniotic membranes could be used for facial nerve repair. The facial nerves of eight rats were dissected and end-to-end anastomosis was performed. Amniotic membranes were covered on the anastomosis sites in four rats. Electromyography results showed that, at the end of the 3rd and 8th weeks after amniotic membrane covering, the latency values of the facial nerves covered by amniotic membranes were significantly shortened and the amplitude values were significantly increased. Compared with simple facial nerve anastomosis, after histopathological examination, facial nerve anastomosed with amniotic membrane showed better continuity, milder inflammatory reactions, and more satisfactory nerve conduction. These findings suggest that amniotic membrane covering has great potential in facial nerve repair. PMID:25206390

  15. Water Mist Suppression in Conjunction with Displacement

    E-print Network

    Hickman, Mark

    Water Mist Suppression in Conjunction with Displacement Ventilation By Benjamin Piers Hume-2758 #12;#12;Displacement Water Mist System Masters of Fire Engineering Thesis 2003 i A man of genius makes Water Mist System Masters of Fire Engineering Thesis 2003 ii #12;Displacement Water Mist System Masters

  16. Torsional stress measurement by axial displacement

    Microsoft Academic Search

    J. J. Deer

    1971-01-01

    An apparatus is described for the measurement of torque by converting angular displacement to axial displacement. A stress-responsive pulley is loosely mounted on a drive shaft by a plain bearing and a short screw-threaded section. The pulley is attached to the shaft by means of a torsion spring. In use a retarding effect upon the pulley causes angular displacement within

  17. Nerve Growth Factor-Dependence of Herpes Simplex Virus Latency in Peripheral Sympathetic and Sensory Neurons in vitro

    Microsoft Academic Search

    C. L. Wilcox; L. Smith; C. R. Freed; E. M. Johnson

    1990-01-01

    Previously, we reported that nerve growth factor (NGF) is required to maintain herpes simplex virus (HSV) latency in cultures of rat sympathetic neurons (Wilcox and Johnson, 1987, 1988). Here, we extend these results by showing that NGF was also required to maintain HSV latency in cultures of sensory neurons obtained from dorsal root ganglia of rats, monkeys, and humans. The

  18. Antisense knock down of TRPA1, but not TRPM8, alleviates cold hyperalgesia after spinal nerve ligation in rats

    Microsoft Academic Search

    Hirokazu Katsura; Koichi Obata; Toshiyuki Mizushima; Hiroki Yamanaka; Kimiko Kobayashi; Yi Dai; Tetsuo Fukuoka; Atsushi Tokunaga; Masafumi Sakagami; Koichi Noguchi

    2006-01-01

    Patients with neuropathic pain frequently experience hypersensitivity to cold stimulation. However, the underlying mechanisms of this enhanced sensitivity to cold are not well understood. After partial nerve injury, the transient receptor potential ion channel TRPV1 increases in the intact small dorsal root ganglion (DRG) neurons in several neuropathic pain models. In the present study, we precisely examined the incidence of

  19. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  20. Cranial nerves XIII and XIV: nerves in the shadows

    PubMed Central

    Bordoni, Bruno; Zanier, Emiliano

    2013-01-01

    It has been known for over a century that these cranial nerves exist, and that they are not typographical errors nor a sensational event reported in the medical literature. A number of scientific articles on anatomy highlight how textbooks on descriptive anatomy do not always consider variables such as differences related to the geographical areas where people live, and these differences do exist. This is an important concept not only for surgeons, but also for all medical professionals who use manual techniques when treating their patients, ie, osteopaths, chiropractors, physiotherapists, and other manual therapists. This paper highlights the latest developments regarding these cranial nerves, offering at the same time some ideas for further reflection when looking at clinical scenarios that appear to bear little relationship to each other. Inclusion of these concepts in everyday anamnesis is encouraged. PMID:23516138

  1. Prospective displacement and velocity-based cine 4D CT.

    PubMed

    Langner, U W; Keall, P J

    2008-10-01

    Four dimensional (4D) computed tomography (CT) image sorting is currently a retrospective procedure. Mismatches in displacement and/or phase of a patient's respiratory signal, corresponding with two dimensional images taken at subsequent couch positions, become visible as artifacts in reconstructed 4D CT images. These artifacts appear as undefined or irregular boundaries in the 4D CT images and cause systematic errors in patient contouring and dose calculations. In addition, the substantially higher dose required for 4D CT, compared with 3D CT, is of concern. To minimize these problems, we developed a prospective respiratory displacement and velocity based cine 4D CT (PDV CT) method to trigger image acquisition if the displacement and velocity of the respiratory signal occurred within predetermined tolerances simultaneously. The use of velocity avoids real-time phase estimation. Real-time image acquisition ensures data sufficiency, while avoiding the need for redundant data. This may potentially result in a lower dose to the patient. PDV CT was compared with retrospective 4D CT acquisition methods, using respiratory signals of 24 lung cancer patients (103 sessions) under free breathing conditions. Image acquisition was simulated for each of these sessions from the respiratory signal. The root mean square (RMS) of differences between displacements and velocities of the respiratory signal corresponding to subsequent images was calculated in order to evaluate the image-sorting accuracy of each method. Patient dose reductions of 22 to 50% were achieved during image acquisition depending on the model parameters chosen. The mean RMS differences over all sessions and image bins show that PDV CT produces similar results to retrospective displacement sorting overall, although improvements of the RMS difference up to 20% were achieved depending on the model parameters chosen. Velocity RMS differences improved between 30 and 45% when compared with retrospective phase sorting. The efficiency in acquisition compared with retrospective phase sorting varied from approximately 10% for displacement and velocity tolerances of 1 mm and 4 mm/s, respectively, to 80 to 93% for 4 mm and 4 mm/s. The lower variation in the displacement and velocity of the respiratory signal in each image bin indicates that PDV CT could be a valuable tool for reducing artifacts in 4D CT images and lowering patient dose, although the cost may be increased acquisition time. PMID:18975697

  2. Free vascularized deep peroneal nerve grafts.

    PubMed

    Koshima, I; Okumoto, K; Umeda, N; Moriguchi, T; Ishii, R; Nakayama, Y

    1996-04-01

    An ideal donor site for vascularized nerve grafts should have a constant anatomy, minimal functional loss after the nerve has been sacrificed, and a dependable blood supply parallel to the nerve over a relatively long distance. Creating a pedicle for a free vascularized deep peroneal nerve graft with the anterior tibial vessels seems to be a most suitable method for repairing long nerve gaps of over 20 cm and digital nerve defects with severe finger damage. Applications of this nerve graft to digital nerve losses with severely scarred beds created by avulsion injury, and two-stage reconstruction in some partial brachial plexus palsies (free vascularized nerve graft in the first stage and free vascularized muscle graft in the second stage) are well indicated. Advantages of this technique are: (1) A long nerve graft (up to 25 cm) can be obtained, and anomalies are rare (the nerve is absent in only 4 percent of cases). (2) The caliber of the vascular pedicle is large (approximately equal to 3 mm). (3) The nerve has a sufficient blood supply from the collateral blood vessels. (4) The graft can be easily obtained in the supine position. (5) A monitoring skin flap, based on the inferior lateral peroneal artery, can be attached to the nerve graft. (6) Sensory loss resulting from the sacrifice of the nerve covers a minimal area. (7) A donor scar on the anterior aspect of the lower leg is more acceptable than one on the posterior aspect because of less movement in walking. Disadvantages of this technique are: (1) Sacrifice of the large vessels in the lower leg may result in circulatory complications in the donor foot; to avoid this problem, preoperative angiography is recommended. (2) The donor scar is in an exposed area in female patients. (3) There may be temporary postoperative edema and disability in the donor leg. PMID:8726331

  3. Changes induced by peripheral nerve injury in the morphology and nanomechanics of sensory neurons

    NASA Astrophysics Data System (ADS)

    Benzina, Ouafa; Szabo, Vivien; Lucas, Olivier; Saab, Marie-belle; Cloitre, Thierry; Scamps, Frédérique; Gergely, Csilla; Martin, Marta

    2013-06-01

    Peripheral nerve injury in vivo promotes a regenerative growth in vitro characterized by an improved neurite regrowth. Knowledge of the conditioning injury effects on both morphology and mechanical properties of live sensory neurons could be instrumental to understand the cellular and molecular mechanisms leading to this regenerative growth. In the present study, we use differential interference contrast microscopy, fluorescence microscopy and atomic force microscopy (AFM) to show that conditioned axotomy, induced by sciatic nerve injury, does not increase somatic size of sensory neurons from adult mice lumbar dorsal root ganglia but promotes the appearance of longer and larger neurites and growth cones. AFM on live neurons is also employed to investigate changes in morphology and membrane mechanical properties of somas of conditioned neurons following sciatic nerve injury. Mechanical analysis of the soma allows distinguishing neurons having a regenerative growth from control ones, although they show similar shapes and sizes.

  4. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  5. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas.

    PubMed

    Macias, M Y; Lehman, C T; Sanger, J R; Riley, D A

    1998-12-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies. PMID:9843078

  6. The transthyretin gene is expressed in Schwann cells of peripheral nerves.

    PubMed

    Murakami, Tatsufumi; Ohsawa, Yutaka; Zhenghua, Li; Yamamura, Ken-Ichi; Sunada, Yoshihide

    2010-08-12

    Transthyretin (TTR) is mainly expressed in the liver and choroid plexus of the brain. The majority of familial amyloidotic polyneuropathy cases are caused by a mutant TTR gene. The origin of the TTR deposited in the peripheral nervous system is unknown. We studied the expression of TTR in the peripheral nerves of normal mice and transgenics bearing the human mutant TTR in a mouse Ttr-null background. Using RT-PCR, Ttr and TTR mRNA was observed in both dorsal root ganglia and sciatic nerves. Ttr mRNA was detected in cultured mouse Schwann cells and the immortalized mouse Schwann cell line, IMS32 cells. Human TTR mRNA and protein were detected in cultured Schwann cells derived from the transgenic mice. We conclude that the TTR gene is expressed in the Schwann cells of peripheral nerves. PMID:20547140

  7. Presynaptic inhibition of soleus Ia afferents does not vary with center of pressure displacements during upright standing.

    PubMed

    Johannsson, J; Duchateau, J; Baudry, S

    2015-07-01

    The present work was designed to investigate the presynaptic modulation of soleus Ia afferents with the position and the direction of the displacement of the center of pressure (CoP) during unperturbed upright standing and exaggerated CoP displacements in young adults. Hoffmann (H) reflex was evoked in the soleus by stimulating the tibial nerve at the knee level. Modulation of Ia presynaptic inhibition was assessed by conditioning the H reflex with fibular nerve (D1 inhibition) and femoral nerve (heteronymous facilitation) stimulation. Leg muscle activity was assessed by electromyography (EMG). The results indicate that in unperturbed standing and exaggerated CoP displacements, the H-reflex amplitude was greater during forward than backward CoP direction (p<0.05). However, the amplitude of the conditioned H reflex (expressed relative to unconditioned H reflex) did not vary with CoP displacement, regardless of the experimental condition. The soleus EMG was greater during forward than backward CoP direction and during anterior than posterior position in both experimental conditions (p<0.05). The modulation of the unconditioned H reflex with CoP direction was positively associated with the corresponding changes in soleus EMG (r(2)>0.34). The tibialis anterior EMG did not change during unperturbed standing, but was greater for backward than forward CoP direction during exaggerated CoP displacements. In this experimental condition, soleus EMG was negatively associated with tibialis anterior EMG (r(2)=0.81). These results indicate that Ia presynaptic inhibition is not modulated with CoP direction and position, but rather suggest that CoP displacements induced changes in excitability of the soleus motor neuron pool. PMID:25869621

  8. Effects of age on nerve fibers in the rhesus monkey optic nerve.

    PubMed

    Sandell, J H; Peters, A

    2001-01-22

    During normal aging there is a reduction in white matter volume in the cerebral hemispheres and structural abnormalities in myelin in some parts of the central nervous system, but whether nerve fibers are lost with age and whether the myelin changes are ubiquitous is not known. Studying the optic nerve, which is a circumscribed bundle of nerve fibers, offers an opportunity to gain further insight into the effects of normal aging on white matter. The present study examined the optic nerves from young (4-10 years) and old (27-33 years) rhesus monkeys using light and electron microscopy. These nerves had been perfused transcardially to obtain optimal preservation of the tissue. Varying degrees of degeneration were encountered in all the optic nerves from the old monkeys. The changes included myelin abnormalities, similar to those reported in other parts of the central nervous system; the presence of degenerating axons and their sheaths; changes in neuroglial cells; and thickening of the trabeculae of connective tissue in the nerve. The total number of nerve fibers was reduced from an average of 1.6 x 10(6) in the young optic nerves to as few as 4 x 10(5) in one old monkey, and with one exception in all of the old optic nerves the packing density of nerve fibers was less than in any of the young optic nerves. The degenerative changes were most marked in those optic nerves that contained the fewest nerve fibers. PMID:11135234

  9. Nerve guides manufactured from photocurable polymers to aid peripheral nerve repair.

    PubMed

    Pateman, Christopher J; Harding, Adam J; Glen, Adam; Taylor, Caroline S; Christmas, Claire R; Robinson, Peter P; Rimmer, Steve; Boissonade, Fiona M; Claeyssens, Frederik; Haycock, John W

    2015-05-01

    The peripheral nervous system has a limited innate capacity for self-repair following injury, and surgical intervention is often required. For injuries greater than a few millimeters autografting is standard practice although it is associated with donor site morbidity and is limited in its availability. Because of this, nerve guidance conduits (NGCs) can be viewed as an advantageous alternative, but currently have limited efficacy for short and large injury gaps in comparison to autograft. Current commercially available NGC designs rely on existing regulatory approved materials and traditional production methods, limiting improvement of their design. The aim of this study was to establish a novel method for NGC manufacture using a custom built laser-based microstereolithography (?SL) setup that incorporated a 405 nm laser source to produce 3D constructs with ? 50 ?m resolution from a photocurable poly(ethylene glycol) resin. These were evaluated by SEM, in vitro neuronal, Schwann and dorsal root ganglion culture and in vivo using a thy-1-YFP-H mouse common fibular nerve injury model. NGCs with dimensions of 1 mm internal diameter × 5 mm length with a wall thickness of 250 ?m were fabricated and capable of supporting re-innervation across a 3 mm injury gap after 21 days, with results close to that of an autograft control. The study provides a technology platform for the rapid microfabrication of biocompatible materials, a novel method for in vivo evaluation, and a benchmark for future development in more advanced NGC designs, biodegradable and larger device sizes, and longer-term implantation studies. PMID:25725557

  10. Bilateral variations of brachial plexus involving the median nerve and lateral cord: An anatomical case study with clinical implications.

    PubMed

    Butz, James J; Shiwlochan, Devina G; Brown, Kevin C; Prasad, Alathady M; Murlimanju, Bukkambudhi V; Viswanath, Srikanteswara

    2014-01-01

    During the routine dissection of upper limbs of a Caucasian male cadaver, variations were observed in the brachial plexus. In the right extremity, the lateral cord was piercing the coracobrachialis muscle. The musculocutaneous nerve and lateral root of the median nerve were observed to be branching inferior to the lower attachment of coracobrachialis muscle. The left extremity exhibited the passage of the median nerve through the flat tendon of the coracobrachialis muscle near its distal insertion into the medial surface of the body of humerus. A variation in the course and branching of the nerve might lead to variant or dual innervation of a muscle and, if inappropriately compressed, could result in a distal neuropathy. Identification of these variants of brachial plexus plays an especially important role in both clinical diagnosis and surgical practice. PMID:24944720

  11. Ginsenoside Re Promotes Nerve Regeneration by Facilitating the Proliferation, Differentiation and Migration of Schwann Cells via the ERK- and JNK-Dependent Pathway in Rat Model of Sciatic Nerve Crush Injury.

    PubMed

    Wang, Lei; Yuan, Damin; Zhang, Dongmei; Zhang, Weidong; Liu, Chun; Cheng, Hongbing; Song, Yan; Tan, Qian

    2015-08-01

    Exploring effective drugs that are capable of promoting nerve regeneration has gained much attention. Ginsenoside Re (Re) is the main ingredient of ginseng berries and roots. Research in the area has shown that ginsenoside Re exhibits multiple pharmacological activities via different mechanisms both in vivo and in vitro. But the potential therapeutic effects of Re on sciatic nerve crush injury (SNC) have been little investigated. Herein, we investigated the protect effect of Re on peripheral nerve regeneration in a rat SNC model. Walking track analysis revealed that Re treatment significantly promoted functional recovery of crushed sciatic nerve in rats. The expression of PCNA in rat sciatic nerve was up-regulated by Re treatment, and peaked when the concentration of Re was 2.0 mg/kg. Using immunofluorescent staining, we found that Re greatly increased the expression of GAP-43 and S100 in injured rat sciatic nerve. Furthermore, we evaluated the effects of Re on proliferation, differentiation, and migration of Schwann cells in SNC rat models. Our studies reveal that Re promotes nerve regeneration is depend on ERK1/2 and JNK1/2 signaling pathway. Elevated Oct-6 expression and featured morphological changes indicated that Re facilitated the differentiation of Schwann cells following SNC. Also, transwell and wound-healing assay demonstrated that the migration capabilities of Schwann cell were significantly enhanced after Re treatment. PMID:25776135

  12. Optimum Small Optical Beam Displacement Measurement

    E-print Network

    Hsu, M T L; Lam, P K; Bowen, W P; Hsu, Magnus T.L.; Delaubert, Vincent; Lam, Ping Koy; Bowen, Warwick

    2004-01-01

    We derive the quantum noise limit for the optical beam displacement of a TEM00 mode. Using a multimodal analysis, we show that the conventional split detection scheme for measuring beam displacement is non-optimal with 80% efficiency. We propose a new displacement measurement scheme that is optimal for small beam displacement. This scheme utilises a homodyne detection setup that has a TEM10 mode local oscillator. We show that although the quantum noise limit to displacement measurement can be surpassed using squeezed light in appropriate spatial modes for both schemes, the TEM10 homodyning scheme out-performs split detection for all values of squeezing.

  13. Optimum Small Optical Beam Displacement Measurement

    E-print Network

    Magnus T. L. Hsu; Vincent Delaubert; Ping Koy Lam; Warwick Bowen

    2004-07-27

    We derive the quantum noise limit for the optical beam displacement of a TEM00 mode. Using a multimodal analysis, we show that the conventional split detection scheme for measuring beam displacement is non-optimal with 80% efficiency. We propose a new displacement measurement scheme that is optimal for small beam displacement. This scheme utilises a homodyne detection setup that has a TEM10 mode local oscillator. We show that although the quantum noise limit to displacement measurement can be surpassed using squeezed light in appropriate spatial modes for both schemes, the TEM10 homodyning scheme out-performs split detection for all values of squeezing.

  14. BLACK ROOT ROT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black Root Rot Prepared by G. S. Abawi, Revised by L.E. Hanson Black root rot is caused by Thielaviopsis basicola (syn. Chalara elegans). The pathogen is widely distributed, can infect more than 130 plant species in 15 families, and causes severe black root rot diseases in ornamentals and crops suc...

  15. Mechanisms of nerve injury in leprosy.

    PubMed

    Scollard, David M; Truman, Richard W; Ebenezer, Gigi J

    2015-01-01

    All patients with leprosy have some degree of nerve involvement. Perineural inflammation is the histopathologic hallmark of leprosy, and this localization may reflect a vascular route of entry of Mycobacterium leprae into nerves. Once inside nerves, M. leprae are ingested by Schwann cells, with a wide array of consequences. Axonal atrophy may occur early in this process; ultimately, affected nerves undergo segmental demyelination. Knowledge of the mechanisms of nerve injury in leprosy has been greatly limited by the minimal opportunities to study affected nerves in man. The nine-banded armadillo provides the only animal model of the pathogenesis of M. leprae infection. New tools available for this model enable the study and correlation of events occurring in epidermal nerve fibers, dermal nerves, and nerve trunks, including neurophysiologic parameters, bacterial load, and changes in gene transcription in both neural and inflammatory cells. The armadillo model is likely to enhance understanding of the mechanisms of nerve injury in leprosy and offers a means of testing proposed interventions. PMID:25432810

  16. Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions

    E-print Network

    Muller, Jean-Michel

    Reciprocation, Square Root, Inverse Square Root, and Some Elementary Functions Using Small with the computation of reciprocals, square roots, inverse square roots, and some elementary functions using small/number of multipliers and compare with other related methods. Index TermsÐReciprocal, square root, inverse square root

  17. A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors

    PubMed Central

    Shentu, Nanying; Zhang, Hongjian; Li, Qing; Zhou, Hongliang; Tong, Renyuan; Li, Xiong

    2012-01-01

    Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency. PMID:22368467

  18. Responses of pulpal nerves to cavity preparation in rat molars: an immunohistochemical study using neurofilament protein (NFP) antiserum.

    PubMed

    Sato, O

    1989-10-01

    The response of neural elements to a dentin injury was morphologically investigated in rat molars by use of immunostaining for neurofilament protein (NFP). An artificially formed cavity in dentin by drilling rapidly caused the displacement of some odontoblasts into the exposed dentinal tubules, while others were detached from the predentin. The subodontoblastic nerve plexus consisting of NFP-immunoreactive nerves shifted inward together with the separated odontoblasts, while a movement of the nerves into the exposed dentinal tubules was not recognized. The odontoblasts separated from the predentin degenerated and disappeared one day after the cavity preparation; at this time, the subodontoblastic nerve plexus underlying the drilled dentin was remarkably disrupted, presumably losing dentinal sensation of the drilled area. Three days after the cavity preparation, the destroyed odontoblastic layer began to be repaired by newly differentiating odontoblasts; the reparative dentin was produced from 5 to 7 days onward. Numerous NFP-positive nerves, beaded in type, gathered in the odontoblastic layer in accordance with the differentiation of the new odontoblasts. The increased beaded nerve fibers were suggested to represent peptide-containing nerves. In 10-15 days, the reparative dentin accumulated quite remarkably under the cavity area. The NFP-positive subodontoblastic nerve plexus was entirely reconstituted and also regained continuity to its surrounding plexus. The nerve fibers in the reconstituted plexus were mostly non-beaded in type as seen in the control teeth. Since dentinal tubules in the reparative dentin are not normally continuous to the primary dentinal tubules, dentinal sensation may not have been restored. PMID:2513855

  19. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1995-05-30

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.

  20. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

    1999-01-01

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

  1. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1999-04-06

    A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 23 figs.

  2. Genetics of bovine abomasal displacement.

    PubMed

    Zerbin, Ina; Lehner, Stefanie; Distl, Ottmar

    2015-04-01

    Displacement of the abomasum (DA) is a common inherited condition in Holstein cows. This article reviews the genetics of DA including risk factors, genetic parameters and molecular genetic results. Breeds other than Holsteins affected by DA include Guernseys, Jerseys, Brown Swiss, Ayrshires and Simmental-Red Holsteins. In most DA cases, left displacements of the abomasum (LDA) are seen. Lactation incidence rates are higher for DA in first lactation Holsteins compared to later lactations. For Holstein cows, heritability estimates for DA are between 0.03 and 0.53. Genetic correlation estimates among DA and milk production traits range from positive to negative. Genome-wide significant genomic regions associated with LDA are located on bovine chromosomes (BTA) 1, 3, 11, 20 and 23. Motilin-associated single nucleotide polymorphisms on BTA23 exhibit a functional relationship with LDA. Pathways for deposition of calcium, insulin-dependent diabetes mellitus and synaptic transmission are significantly related to LDA in Holsteins. Deciphering the DA-associated genomic regions and genes may be an important step in the quest to understand the underlying disease-causing mechanisms and in unravelling mutations with a causal relationship to DA. PMID:25840863

  3. Displacement Based Multilevel Structural Optimization

    NASA Technical Reports Server (NTRS)

    Sobieszezanski-Sobieski, J.; Striz, A. G.

    1996-01-01

    In the complex environment of true multidisciplinary design optimization (MDO), efficiency is one of the most desirable attributes of any approach. In the present research, a new and highly efficient methodology for the MDO subset of structural optimization is proposed and detailed, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures is performed. In the system level optimization, the design variables are the coefficients of assumed polynomially based global displacement functions, and the load unbalance resulting from the solution of the global stiffness equations is minimized. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. The approach is expected to prove very efficient since the design task is broken down into a large number of small and efficient subtasks, each with a small number of variables, which are amenable to parallel computing.

  4. An alternative to the classical nerve graft for the management of the short nerve gap.

    PubMed

    Dellon, A L; Mackinnon, S E

    1988-11-01

    Reconstruction of a short nerve gap by a nerve graft produces donor-site scarring, loss of donor nerve function, and neuroma formation. This study compared the regeneration achieved after 1 year in 16 monkeys across a 3-cm upper arm ulnar nerve gap with a bioabsorbable polyglycolic acid nerve conduit with the regeneration achieved with a classical interfascicular interpositional sural nerve graft. The results demonstrated electrophysiologic and histologic evidence of neural regeneration across the gaps in all experimental groups. The bioabsorbable nerve conduit groups and the sural nerve graft group had mean fiber diameters, amplitudes, and conduction velocities each significantly less than those of normal control ulnar nerves. There was, however, no significant difference between any of the experimental groups. Electromyography demonstrated recovery of 19 of the 28 (68 percent) intrinsic muscles studied. These results demonstrate that the primate peripheral nerve can regenerate across short nerve gaps when guided by an appropriate nerve conduit, suggesting that a single-stage biodegradable polyglycolic acid conduit may be used as an alternative to a short interfascicular nerve graft. PMID:2845455

  5. Use of nerve elongator to repair short-distance peripheral nerve defects: a prospective randomized study

    PubMed Central

    Bai, Lu; Wang, Tian-bing; Wang, Xin; Zhang, Wei-wen; Xu, Ji-hai; Cai, Xiao-ming; Zhou, Dan-ya; Cai, Li-bing; Pan, Jia-dong; Tian, Min-tao; Chen, Hong; Zhang, Dian-ying; Fu, Zhong-guo; Zhang, Pei-xun; Jiang, Bao-guo

    2015-01-01

    Repair techniques for short-distance peripheral nerve defects, including adjacent joint flexion to reduce the distance between the nerve stump defects, “nerve splint” suturing, and nerve sleeve connection, have some disadvantages. Therefore, we designed a repair technique involving intraoperative tension-free application of a nerve elongator and obtained good outcomes in the repair of short-distance peripheral nerve defects in a previous animal study. The present study compared the clinical outcomes between the use of this nerve elongator and performance of the conventional method in the repair of short-distance transection injuries in human elbows. The 3-, 6-, and 12-month postoperative follow-up results demonstrated that early neurological function recovery was better in the nerve elongation group than in the conventional group, but no significant difference in long-term neurological function recovery was detected between the two groups. In the nerve elongation group, the nerves were sutured without tension, and the duration of postoperative immobilization of the elbow was decreased. Elbow function rehabilitation was significantly better in the nerve elongation group than in the control group. Moreover, there were no security risks. The results of this study confirm that the use of this nerve elongator for repair of short-distance peripheral nerve defects is safe and effective. PMID:25788924

  6. Sciatic nerve regeneration using a nerve growth factor-containing fibrin glue membrane

    PubMed Central

    Ma, Shengzhong; Peng, Changliang; Wu, Shiqing; Wu, Dongjin; Gao, Chunzheng

    2013-01-01

    Our previous findings confirmed that the nerve growth factor-containing fibrin glue membrane provides a good microenvironment for peripheral nerve regeneration; however, the precise mechanism remains unclear. p75 neurotrophin receptor (p75NTR) plays an important role in the regulation of peripheral nerve regeneration. We hypothesized that a nerve growth factor-containing fibrin glue membrane can promote neural regeneration by up-regulating p75NTR expression. In this study, we used a silicon nerve conduit to bridge a 15 mm-long sciatic nerve defect and injected a mixture of nerve growth factor and fibrin glue at the anastomotic site of the nerve conduit and the sciatic nerve. Through RT-PCR and western blot analysis, nerve growth factor-containing fibrin glue membrane significantly increased p75NTR mRNA and protein expression in the Schwann cells at the anastomotic site, in particular at 8 weeks after injection of the nerve growth factor/fibrin glue mixture. These results indicate that nerve growth factor-containing fibrin glue membrane can promote peripheral nerve regeneration by up-regulating p75NTR expression in Schwann cells. PMID:25206664

  7. Nanofibrous nerve conduits for repair of 30-mm-long sciatic nerve defects

    PubMed Central

    Biazar, Esmaeil; Keshel, Saeed Heidari; Pouya, Majid; Rad, Hadi; Nava, Melody Omrani; Azarbakhsh, Mohammad; Hooshmand, Shirin

    2013-01-01

    It has been confirmed that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit can promote peripheral nerve regeneration in rats. However, its efficiency in repair of over 30-mm-long sciatic nerve defects needs to be assessed. In this study, we used a nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve conduit implantation, regenerated nerves were cally observed and histologically assessed. In the nanofibrous graft, the rat sciatic nerve trunk had been reconstructed by restoration of nerve continuity and formation of myelinated nerve fiber. There were Schwann cells and glial cells in the regenerated nerves. Masson's trichrome staining showed that there were no pathological changes in the size and structure of gastrocnemius muscle cells on the operated side of rats. These findings suggest that nanofibrous poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit is suitable for repair of long-segment sciatic nerve defects. PMID:25206536

  8. Assesing tree-root & soil interaction using pull-out test apparatus

    NASA Astrophysics Data System (ADS)

    Wibowo, J.; Corcoran, M. K.; Kala, R.; Leavell, D.

    2011-12-01

    Knowing in situ root strength provides a better understanding of the responses of tree root systems against external loads. Root pullout devices are used to record these strengths and can be expressed in two ways: pullout force, which is a direct output from the load cell (measured in pounds) or pullout stress, which is the pullout force divided by root cross section area (measured in pounds per square in.). Pullout tests show not only the possible tensile strength of a tree root, but also the interaction between the tree root and the surrounding geological materials. After discussion with engineers from the University of Nottingham-Trent, the U.S. Army Engineer Research and Development Center (ERDC) constructed a root pullout apparatus with some modifications. These modifications included using a T-System configuration at the base of an aluminum frame instead of a diagonal rod and varying the size of the clamp placed around the tested root. The T-System is placed in front of the root perpendicular to the root path. In the ERDC pullout device, the root was pulled directly without a lever system. A string pot was used to measure displacement when the root was pulled. The device is capable of pulling tree roots with a diameter of up to 2.5 in. and a maximum load of 5000 lbs. Using this device, ERDC conducted field operations in Portland, Oregon; Burlington, Washington; and Albuquerque, New Mexico, on Oregon ash, alder, maple, and cedar trees. In general, pullout tests were conducted approximately 60 deg around the tree selected for the tests. The location of a test depended on the availability of a root near the ground surface. A backhoe was used to remove soil around the tree to locate roots. Before the root was secured in a clamp, root diameter was measured and recorded, and the root was photographed. The tree species, dip angle and dip direction of the root, root location with respect to the tree, tree location, dates, weather, and soil type were also recorded. When the test begins the load cell and displacement transducers immediately started recording the measurements, and the measurements are stored on a laptop computer. The hydraulic pump controls the rate of loading for a relatively slow pulling displacement rate of 0.08 in./sec. Failure occurred when the root breaks or was pulled out of the soil. Maximum forces and root failure location were noted, as well as any additional observations during and after the test. In the ERDC tests, root diameters (root with bark) ranged between 0.7 and 2.33 in., the pullout force was between 86 and 3513 lb, and the pullout stress was between 56 and 2645 psi. ERDC recorded three different types of tree-root failures: pure root tensile failure, bonding between root and soil failure, and a combination of the two. In tensile failure, a root breaks abruptly and the force versus displacement curve usually shows a steep slope, and there is no residual strength. In a bonding failure, the force versus displacement curve shows a gentler slope, and there is residual strength. A combined failure mode may also occur. For pullout tests conducted for the ERDC research, the combined mode failure was the most prevalent failure mechanism.

  9. Posterior approach for both spinal accessory nerve to suprascapular nerve and triceps branch to axillary nerve for upper plexus injuries.

    PubMed

    Bhandari, P S; Deb, Prabal

    2013-01-01

    Restoration of stability and movements at the shoulder joint are the 2 most important goals in the management of brachial plexus injuries. The 2 nerves that are preferentially targeted for this purpose are the suprascapular (SSN) and the axillary (AXN) nerves. These nerve transfers have conventionally been performed by the anterior approach, but recently transfers performed by posterior incisions have been gaining popularity, by virtue of being selective and located close to the target muscles. Herein, we describe the technical details of spinal accessory nerve (SAN) to SSN and triceps branch to AXN for upper plexus injuries, both performed by the posterior approach. PMID:23261196

  10. Saphenous nerve innervation of the medial ankle

    PubMed Central

    Clendenen, Steven R; Whalen, Joseph L

    2013-01-01

    Background The distal saphenous nerve is commonly known to provide cutaneous innervation of the medial side of the ankle and distally to the base of the great toe. We hypothesize that the saphenous nerve innervates the periosteum of the medial malleolus and joint capsule. Methods Five fresh limbs were dissected and the saphenous nerve was traced distally with magnification. The medial malleolus, talus, and soft tissue were fixed in formaldehyde, decalcified, and embedded in paraffin and sectioned. Histologic slides were then prepared using S100 antibody nerve stains. Results Histologic slides were examined and myelinated nerves could be observed within the medial capsule and periosteum in all the specimens. Conclusion We have demonstrated that the saphenous nerve innervates the periosteum of the medial malleolus and joint capsule. PMID:23630434

  11. Imaging the Facial Nerve: A Contemporary Review

    PubMed Central

    Gupta, Sachin; Mends, Francine; Hagiwara, Mari; Fatterpekar, Girish; Roehm, Pamela C.

    2013-01-01

    Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell's palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers. PMID:23766904

  12. Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

    SciTech Connect

    Tsoumakidou, Georgia, E-mail: gtsoumakidou@yahoo.com; Garnon, Julien, E-mail: juliengarnon@gmail.com; Ramamurthy, Nitin, E-mail: nitin_ramamurthy@hotmail.com; Buy, Xavier, E-mail: xbuy@ymail.com; Gangi, Afshin, E-mail: gangi@unistra.fr [University Hospital of Strasbourg (France)] [University Hospital of Strasbourg (France)

    2013-12-15

    Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO{sub 2} insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

  13. Quantification of gene expression after painful nerve injury: validation of optimal reference genes.

    PubMed

    Bangaru, Madhavi Latha Yadav; Park, Frank; Hudmon, Andy; McCallum, J Bruce; Hogan, Quinn H

    2012-03-01

    Stably expressed housekeeping genes (HKGs) are necessary for standardization of transcript measurement by quantitative real-time polymerase chain reaction (qRT-PCR). Peripheral nerve injury disrupts expression of numerous genes in sensory neurons, but the stability of conventional HKGs has not been tested in this context. We examined the stability of candidate HKGs during nerve injury, including the commonly used 18S ribosomal RNA, ?-tubulin I and ?-tubulin III, actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and hypoxanthine phosphoribosyltransferase 1 (HPRT1), and mitogen-activated protein kinase 6 (MAPK6). Total RNA for cDNA synthesis was isolated from dorsal root ganglia of rats at 3, 7, and 21 days following either skin incision alone or spinal nerve ligation, after which the axotomized and adjacent ganglia were analyzed separately. Relative stability of HKGs was determined using statistical algorithms geNorm and NormFinder. Both analyses identified MAPK6 and GAPDH as the two most stable HKGs for normalizing gene expression for qRT-PCR analysis in the context of peripheral nerve injury. Our findings indicate that a prior analysis of HKG expression levels is important for accurate normalization of gene expression in models of nerve injury. PMID:21863315

  14. The Effects of Irreversible Electroporation (IRE) on Nerves

    Microsoft Academic Search

    Wei Li; Qingyu Fan; Zhenwei Ji; Xiuchun Qiu; Zhao Li; Ilya Ulasov

    2011-01-01

    BackgroundIf a critical nerve is circumferentially involved with tumor, radical surgery intended to cure the cancer must sacrifice the nerve. Loss of critical nerves may lead to serious consequences. In spite of the impressive technical advancements in nerve reconstruction, complete recovery and normalization of nerve function is difficult to achieve. Though irreversible electroporation (IRE) might be a promising choice to

  15. Renal tubular acidosis and nerve deafness.

    PubMed Central

    Dunger, D B; Brenton, D P; Cain, A R

    1980-01-01

    Two brothers are described with renal tubular acidosis and nerve deafness: the elder also had rickets and hypokalaemia. The parents were unaffected. Studies of urinary acidification and bicarbonate excretion were consistent with a distal tubular abnormality. This report strengthens the view previously proposed in similar cases that nerve deafness and renal tubular acidosis constitute a genetic entity. Examination for nerve deafness is indicated in any child with renal tubular acidosis. Images Fig. 2 PMID:7387165

  16. Nerve Conduction Studies in Multiple System Atrophy

    Microsoft Academic Search

    Michael Abele; Jörg B. Schulz; Katrin Bürk; Helge Topka; Johannes Dichgans; Thomas Klockgether

    2000-01-01

    To study the frequency and severity of peripheral neuropathy in multiple system atrophy (MSA), we performed nerve conduction studies in 42 MSA patients suffering from either cerebellar MSA (MSA-C) or parkinsonian MSA (MSA-P). Abnormal nerve conduction was present in 24% of the patients. Abnormalities were significantly more frequent in MSA-P (43%) compared to MSA-C (14%). Motor nerve conduction velocities were

  17. Hyperalgesic actions of cytokines on peripheral nerves

    Microsoft Academic Search

    Robert R. Myers; Rochelle Wagner; Linda S. Sorkin

    \\u000a The relationship between nerve injury and pain is pervasive in medicine, being both a simple, common experience and an important\\u000a diagnostic tool. Acute trauma to a nerve is almost always painful and has been experienced by many people in association with\\u000a sports and workplace activities. In these cases, injuries occur usually because of nerve stretching or compression, damaging\\u000a sensory axons

  18. Nerve Signal Processing using Artificial Neural Nets

    Microsoft Academic Search

    Martin Bogdan; Alexei Babanine; Jörg Kaniecki; Wolfgang Rosenstiel

    1995-01-01

    In this paper we review the aim of the INTER1-project (Intelligent Neural InTERface), especiallyfrom the point of view of Artificial Neural Nets (ANN). We also propose a modus operandi to processreal nerve signals using ANN. We present a method to simulate nerve signals, first experience inseparating nerve signals from multi-array recorded data as well as first experiences using an artificialneural

  19. Staphylococcus aureus infection of the optic nerve.

    PubMed

    Osmanovic, Senad; Al-Heeti, Omar M; Lin, Amy Y; Zivin, Sean P; Justo, Julie Ann; Mayer, Stockton M; Aakalu, Vinay K; Moss, Heather E; Patel, Mahesh C

    2015-03-01

    A 71-year-old woman presented with painful vision loss in the right eye followed by ophthalmoplegia. Magnetic resonance imaging demonstrated optic nerve sheath enlargement and enhancement. Biopsy of the optic nerve sheath revealed purulent and necrotic material that was positive for methicillin-sensitive Staphylococcus aureus. The patient underwent enucleation of the right eye and was treated with systemic antibiotics with clinical stabilization. Imaging, pathological and treatment aspects of optic nerve sheath abscess are discussed. PMID:25383588

  20. Use new PLGL-RGD-NGF nerve conduits for promoting peripheral nerve regeneration

    PubMed Central

    2012-01-01

    Background Nerve conduits provide a promising strategy for peripheral nerve injury repair. However, the efficiency of nerve conduits to enhance nerve regeneration and functional recovery is often inferior to that of autografts. Nerve conduits require additional factors such as cell adhesion molecules and neurotrophic factors to provide a more conducive microenvironment for nerve regeneration. Methods In the present study, poly{(lactic acid)-co-[(glycolic acid)-alt-(L-lysine)]} (PLGL) was modified by grafting Gly-Arg-Gly-Asp-Gly (RGD peptide) and nerve growth factor (NGF) for fabricating new PLGL-RGD-NGF nerve conduits to promote nerve regeneration and functional recovery. PLGL-RGD-NGF nerve conduits were tested in the rat sciatic nerve transection model. Rat sciatic nerves were cut off to form a 10 mm defect and repaired with the nerve conduits. All of the 32 Wistar rats were randomly divided into 4 groups: group PLGL-RGD-NGF, group PLGL-RGD, group PLGL and group autograft. At 3 months after surgery, the regenerated rat sciatic nerve was evaluated by footprint analysis, electrophysiology, and histologic assessment. Experimental data were processed using the statistical software SPSS 10.0. Results The sciatic function index value of groups PLGL-RGD-NGF and autograft was significantly higher than those of groups PLGL-RGD and PLGL. The nerve conduction velocities of groups PLGL-RGD-NGF and autograft were significantly faster than those of groups PLGL-RGD and PLGL. The regenerated nerves of groups PLGL-RGD-NGF and autograft were more mature than those of groups PLGL-RGD and PLGL. There was no significant difference between groups PLGL-RGD-NGF and autograft. Conclusions PLGL-RGD-NGF nerve conduits are more effective in regenerating nerves than both PLGL-RGD nerve conduits and PLGL nerve conduits. The effect is as good as that of an autograft. This work established the platform for further development of the use of PLGL-RGD-NGF nerve conduits for clinical nerve repair. PMID:22776032

  1. Sciatic nerve repair by acellular nerve xenografts implanted with BMSCs in rats xenograft combined with BMSCs.

    PubMed

    Jia, Hua; Wang, Ying; Tong, Xiao-Jie; Liu, Gui-Bo; Li, Qi; Zhang, Li-Xin; Sun, Xiao-Hong

    2012-03-01

    Acellular nerves possess the structural and biochemical features similar to those of naive endoneurial tubes, and have been proved bioactive for allogeneil graft in nerve tissue engineering. However, the source of allogenic donators is restricted in clinical treatment. To explore sufficient substitutes for acellular nerve allografts (ANA), we investigated the effectiveness of acellular nerve xenografts (ANX) combined with bone marrow stromal cells (BMSCs) on repairing peripheral nerve injuries. The acellular nerves derived from Sprague-Dawley rats and New Zealand rabbits were prepared, respectively, and BMSCs were implanted into the nerve scaffolds and cultured in vitro. All the grafts were employed to bridge 1 cm rat sciatic nerve gaps. Fifty Wistar rats were randomly divided into five groups (n = 10 per group): ANA group, ANX group, BMSCs-laden ANA group, BMSCs-laden ANX group, and autologous nerve graft group. At 8 weeks post-transplantation, electrophysiological study was performed and the regenerated nerves were assayed morphologically. Besides, growth-promoting factors in the regenerated tissues following the BMSCs integration were detected. The results indicated that compared with the acellular nerve control groups, nerve regeneration and functional rehabilitation for the xenogenic nerve transplantation integrated with BMSCs were advanced significantly, and the rehabilitation efficacy was comparable with that of the autografting. The expression of neurotrophic factors in the regenerated nerves, together with that of brain-derived neurotrophic factor (BDNF) in the spinal cord and muscles were elevated largely. In conclusion, ANX implanted with BMSCs could replace allografts to promote nerve regeneration effectively, which offers a reliable approach for repairing peripheral nerve defects. PMID:22127791

  2. Raman microspectroscopy for visualization of peripheral nerves

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Harada, Yoshinori; Koizumi, Noriaki; Takamatsu, Tetsuro

    2013-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery is essential for improving quality of life of patients. To preserve peripheral nerves, detection of ne peripheral nerves that cannot be identi ed by human eye or under white light imaging is necessary. In this study, we sought to provide a proof-of-principle demonstration of a label-free detection technique of peripheral nerve tissues against adjacent tissues that employs spontaneous Raman microspectroscopy. A line-illumination confocal Raman microscope was used for the experiment. A laser operating at the wavelength of 532 nm was used as an excitation laser light. We obtained Raman spectra of peripheral nerve, brous connective tissue, skeletal muscle, blood vessel, and adipose tissue of Wistar rats, and extracted speci c spectral features of peripheral nerves and adjacent tissues. By applying multivariate image analysis, peripheral nerves were clearly detected against adjacent tissues without any preprocessing neither xation nor staining. These results suggest the potential of the Raman spectroscopic observation for noninvasive and label-free nerve detection, and we expect this method could be a key technique for nerve-sparing surgery.

  3. Nerve conduction in Frogs and Humans

    NSDL National Science Digital Library

    Elizabeth Vizsolyi (Univ. of British Columbia; )

    1988-06-13

    These exercises are taken from a vertebrate physiology course, and use either a human subject or a dissected frog, thus providing relatively simply alternatives that may suit your needs. Nerve conduction velocity can be measured in the frog sciatic nerve with recordings of the biphasic action potential on the outside of the nerve trunk. Absolute and relative refractory periods can also be determined. Conduction velocity in the human can be obtained from electromyograms taken from the fourth and fifth fingers following stimulation of the ulnar nerve.

  4. Tissue engineered constructs for peripheral nerve surgery

    PubMed Central

    Johnson, P. J.; Wood, M. D.; Moore, A. M.; Mackinnon, S. E.

    2013-01-01

    Summary Background Tissue engineering has been defined as “an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function or a whole organ”. Traumatic peripheral nerve injury resulting in significant tissue loss at the zone of injury necessitates the need for a bridge or scaffold for regenerating axons from the proximal stump to reach the distal stump. Methods A review of the literature was used to provide information on the components necessary for the development of a tissue engineered peripheral nerve substitute. Then, a comprehensive review of the literature is presented composed of the studies devoted to this goal. Results Extensive research has been directed toward the development of a tissue engineered peripheral nerve substitute to act as a bridge for regenerating axons from the proximal nerve stump seeking the distal nerve. Ideally this nerve substitute would consist of a scaffold component that mimics the extracellular matrix of the peripheral nerve and a cellular component that serves to stimulate and support regenerating peripheral nerve axons. Conclusions The field of tissue engineering should consider its challenge to not only meet the autograft “gold standard” but also to understand what drives and inhibits nerve regeneration in order to surpass the results of an autograft. PMID:24385980

  5. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor)

    1991-01-01

    Polyimidazoles (Pl) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethylacetamide, sulfolane, N-methylpyrroldinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperature under nitrogen. The di(hydroxyphenyl)imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl)imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxyphenyl)imidazole monomer. This synthetic route has provided high molecular weight Pl of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

  6. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (inventor); Hergenrother, Paul M. (inventor)

    1992-01-01

    Polyimidazoles (PI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl) imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethyl acetamide, sulfolane, N-methylpyrrolidinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl) imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl) imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxphenyl) imidazole monomer. This synthetic route has provided high molecular weight PI of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

  7. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergerrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1997-01-01

    Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

  8. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  9. Motor Nerve Transfers to Restore Extrinsic Median Nerve Function: Case Report

    PubMed Central

    Hsiao, Eugene C.; Tung, Thomas H.; Mackinnon, Susan E.

    2008-01-01

    Active pronation is important for many activities of daily living. Loss of median nerve function including pronation is a rare sequela of humerus fracture. Tendon transfers to restore pronation are reserved for the obstetrical brachial plexus palsy patient. Transfer of expendable motor nerves is a treatment modality that can be used to restore active pronation. Nerve transfers are advantageous in that they do not require prolonged immobilization postoperatively, avoid operating within the zone of injury, reinnervate muscles in their native location prior to degeneration of the motor end plates, and result in minimal donor deficit. We report a case of lost median nerve function after a humerus fracture. Pronation was restored with transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres branch of the median nerve. Anterior interosseous nerve function was restored with transfer of the supinator branch to the anterior interosseous nerve. Clinically evident motor function was seen at 4 months postoperatively and continued to improve for the following 18 months. The patient has 4+/5 pronator teres, 4+/5 flexor pollicis longus, and 4?/5 index finger flexor digitorum profundus function. The transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres and supinator branch of the radial nerve to the anterior interosseous nerve is a novel, previously unreported method to restore extrinsic median nerve function. PMID:18807095

  10. A Histopathologic and Morphometric Differentiation of Nerves in Optic Nerve Hypoplasia and Leber Hereditary Optic Neuropathy

    Microsoft Academic Search

    Hossein G. Saadati; Hugo Y. Hsu; Keith B. Heller; Alfredo A. Sadun

    Objectives: To characterize and quantitate optic nerve histopathologic and morphometric differences between optic nerve hypoplasia (ONH) as an early and congeni- tal form of intrinsic axonal loss and Leber hereditary op- tic neuropathy (LHON) as a late and acquired form of intrinsic axonal loss. Materials and Methods: Optic nerves from 3 sources were examined: a 42-year-old healthy woman (control), a

  11. The Cranial Nerve Skywalk: A 3D Tutorial of Cranial Nerves in a Virtual Platform

    ERIC Educational Resources Information Center

    Richardson-Hatcher, April; Hazzard, Matthew; Ramirez-Yanez, German

    2014-01-01

    Visualization of the complex courses of the cranial nerves by students in the health-related professions is challenging through either diagrams in books or plastic models in the gross laboratory. Furthermore, dissection of the cranial nerves in the gross laboratory is an extremely meticulous task. Teaching and learning the cranial nerve pathways…

  12. The Effects of Repetitive Compression on Nerve Conduction and Blood Flow in the Rabbit Sciatic Nerve

    Microsoft Academic Search

    Y. Yoshii; Y. Nishiura; N. Terui; Y. Hara; Saijilafu; Naoyuki Ochiai

    2010-01-01

    The objective of this study was to clarify the effect of repetitive compression on nerve physiology in an experimental rabbit model. We defined 80 mmHg as a compression force which caused temporary disturbance of nerve conduction and blood flow with a brief compression. The following compressions were applied for 30 minutes to rabbit sciatic nerves: continuous compression, low frequency release

  13. Effects of graded mechanical compression of rabbit sciatic nerve on nerve blood flow and electrophysiological properties

    Microsoft Academic Search

    Takafumi Yayama; Shigeru Kobayashi; Yoshitaka Nakanishi; Kenzo Uchida; Yasuo Kokubo; Tsuyoshi Miyazaki; Kenichi Takeno; Kosuke Awara; Erisa S. Mwaka; Yukihide Iwamoto; Hisatoshi Baba

    2010-01-01

    Entrapment neuropathy is a frequent clinical problem that can be caused by, among other factors, mechanical compression; however, exactly how a compressive force affects the peripheral nerves remains poorly understood. In this study, using a rabbit model of sciatic nerve injury (n=12), we evaluated the time-course of changes in intraneural blood flow, compound nerve action potentials, and functioning of the

  14. Cranial Nerves any nerve that emanates from the skull Motor = efferent

    E-print Network

    Houde, Peter

    Cranial Nerves ­ any nerve that emanates from the skull Motor = efferent somatomotor ­ to skeletal, vision, gustation, hearing, equilibrium Cranial nerves - functions nI ­ olfactory, SS nII ­ optic, SS n gustation, somatosensory nX ­ vagus, somatomotor to larynx, ANS parasympathetic throughout body nXI ­ spinal

  15. Fiber optic multimode displacement sensor

    NASA Astrophysics Data System (ADS)

    Fisher, Karl A.; Jarzynski, Jacek

    1996-04-01

    An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, Schlieren multimode fiber-optic hydrophone, Applied Physics Letters 37(2), 15 July 1980, p. 145-146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1? OD×3/4?). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz-9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm3 making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications.

  16. Imunoreactivity of zinc transporter 7 (ZNT7) in mouse dorsal root ganglia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the present study, we showed for the first time the localization of ZNT7 immunoreactivity in the mouse dorsal root ganglion (DRG) by means of immunohistochemistry and confocal laser scanning microscopy. Our results revealed that ZNT7 immunoreactivity was abundantly expressed in the nerve cells of...

  17. Displacement of crude oil by carbon dioxide 

    E-print Network

    Omole, Olusegun

    1980-01-01

    DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Submitted to the Graduate College of Texas ASM University in part';al fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1980 Major Subject...: Petroleum Engineering DISPLACEMENT OF CRUDE OIL BY CARBON DIOXIDE A Thesis by OLUSEGUN OMOLE Approved as to style and content by: hairman of Committee / (Member (Member (Member (Hea o Depart ent December 1980 ABSTRACT Displacement of Crude Oil...

  18. Vagal nerve stimulator: Evolving trends.

    PubMed

    Ogbonnaya, Sunny; Kaliaperumal, Chandrasekaran

    2013-01-01

    Over three decades ago, it was found that intermittent electrical stimulation from the vagus nerve produces inhibition of neural processes, which can alter brain activity and terminate seizures. This paved way for the concept of vagal nerve stimulator (VNS). We describe the evolution of the VNS and its use in different fields of medicine. We also review the literature focusing on the mechanism of action of VNS producing desired effects in different conditions. PUBMED and EMBASE search was performed for 'VNS' and its use in refractory seizure management, depression, obesity, memory, and neurogenesis. VNS has been in vogue over for the past three decades and has proven to reduce the intensity and frequency of seizure by 50% in the management of refractory seizures. Apart from this, VNS has been shown to promote neurogenesis in the dentate gyrus of rat hippocampus after 48 hours of stimulation of the vagus nerve. Improvement has also been observed in non-psychotic major depression from a randomized trial conducted 7 years ago. The same concept has been utilized to alter behavior and cognition in rodents, and good improvement has been observed. Recent studies have proven that VNS is effective in obesity management in patients with depression. Several hypotheses have been postulated for the mechanism of action of VNS contributing to its success. VNS has gained significant popularity with promising results in epilepsy surgery and treatment-resistant depression. The spectrum of its use has also extended to other fields of medicine including obesity, memory, and neurogenesis, and there is still a viable scope for its utility in the future. PMID:23633829

  19. Microbial Adhesion in Flow Displacement Systems

    PubMed Central

    Busscher, Henk J.; van der Mei, Henny C.

    2006-01-01

    Flow displacement systems are superior to many other (static) systems for studying microbial adhesion to surfaces because mass transport and prevailing shear conditions can be adequately controlled and notoriously ill-defined slight rinsing steps to remove so-called “loosely adhering organisms” can be avoided. In this review, we present the basic background required to calculate mass transport and shear rates in flow displacement systems, focusing on the parallel plate flow chamber as an example. Critical features in the design of flow displacement systems are discussed, as well as different strategies for data analysis. Finally, selected examples of working with flow displacement systems are given for diverse biomedical applications. PMID:16418527

  20. Macrodystrophia lipomatosa involving multiple nerves.

    PubMed

    Rohilla, Seema; Jain, Nitin; Sharma, Rambaksh; Dhaulakhandi, Dhara B

    2012-03-01

    Macrodystrophia lipomatosa (MDL), a rare congenital disorder, is considered by some to be a localized form of Proteus syndrome. The implication of the PTEN (phosphatase and tensin homolog deleted on chromosome 10) gene in both strengthens this belief. We present a case who had MDL in multiple nerve territories--all on the same side of the body--with hypertrophy of mainly fibroadipose tissue throughout their distribution, thus pointing to a form of localized hemihypertrophy; both hemihypertrophy and lipomatous tumors are components of Proteus syndrome. PMID:21948052

  1. Root canal irrigants

    PubMed Central

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

  2. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Nerve conduction velocity measurement device. 882.1550 Section...Nerve conduction velocity measurement device. (a) Identification...nerve conduction velocity measurement device is a device which...includes the stimulator and the electronic processing equipment...

  3. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Nerve conduction velocity measurement device. 882.1550 Section...Nerve conduction velocity measurement device. (a) Identification...nerve conduction velocity measurement device is a device which...includes the stimulator and the electronic processing equipment...

  4. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Nerve conduction velocity measurement device. 882.1550 Section...Nerve conduction velocity measurement device. (a) Identification...nerve conduction velocity measurement device is a device which...includes the stimulator and the electronic processing equipment...

  5. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Nerve conduction velocity measurement device. 882.1550 Section...Nerve conduction velocity measurement device. (a) Identification...nerve conduction velocity measurement device is a device which...includes the stimulator and the electronic processing equipment...

  6. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Nerve conduction velocity measurement device. 882.1550 Section...Nerve conduction velocity measurement device. (a) Identification...nerve conduction velocity measurement device is a device which...includes the stimulator and the electronic processing equipment...

  7. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Electrical peripheral nerve stimulator. 868...Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator...

  8. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Electrical peripheral nerve stimulator. 868...Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator...

  9. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Electrical peripheral nerve stimulator. 868...Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator...

  10. 21 CFR 868.2775 - Electrical peripheral nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Electrical peripheral nerve stimulator. 868...Monitoring Devices § 868.2775 Electrical peripheral nerve stimulator. (a) Identification. An electrical peripheral nerve stimulator...

  11. Detoxification of Organophosphate Nerve Agents by Immobilized Dual Functional

    E-print Network

    Chen, Wilfred

    Detoxification of Organophosphate Nerve Agents by Immobilized Dual Functional Biocatalysts of organophosphate nerve agents in bulk liquid phase. ß 2005 Wiley Periodicals, Inc. Keywords: pesticides; degradation; OPH; CBD; hollow fiber bioreactor; immobilized cells INTRODUCTION All nerve agents belong

  12. Nerve repair by means of tubulization: past, present, future.

    PubMed

    Konofaos, P; Ver Halen, J P

    2013-03-01

    Peripheral nerve injury may result in injury without gaps or injury with gaps between nerve stumps. In the presence of a nerve defect, the placement of an autologous nerve graft is the current gold standard for nerve restoration. The clinical employment of tubes as an alternative to autogenous nerve grafts is mainly justified by the limited availability of donor tissue for nerve autografts and their related morbidity. The purpose of this review is to present an overview of the literature on the applications of nerve conduits in peripheral nerve repair. Moreover, the different steps that are involved in the design of an ideal nerve conduit for peripheral nerve repair, including the choice of biomaterial, fabrication technique, and the various potential modifications to the common hollow nerve tube, are also discussed. PMID:23303520

  13. The binding of tetrodotoxin to nerve membranes.

    PubMed

    Keynes, R D; Ritchie, J M; Rojas, E

    1971-02-01

    1. The% reduction in size of the externally recorded action potential produced by concentrations of tetrodotoxin (TTX) in the range 6-300 nM was determined for the small non-myelinated fibres of the rabbit cervical vagus nerve and of the walking leg nerves of crab and lobster. The concentration of TTX for 50% reduction was around 80 nM for rabbit vagus and 14 nM for crab nerve.2. Bio-assay procedures were devised to measure the amount of TTX taken up by a nerve when it was exposed to a very small volume of a solution whose TTX content was just great enough to produce 100% block of conduction. The extracellular space of each nerve was determined with [(14)C]sugar so that an allowance could be made for extracellular dilution.3. The TTX binding by rabbit, crab and lobster nerve was respectively 0.064, 0.053 and 0.036 p-mole/mg wet weight of nerve.4. The binding of saxitoxin was measured in rabbit vagus nerve, and found to be much the same as that of TTX.5. Control experiments on rabbit sciatic nerve, where the area of excitable membrane was much smaller, showed that there was relatively little unspecific binding of TTX.6. In view of the evidence presented here and elsewhere that the blocking of sodium conductance by TTX involves the attachment of only one TTX molecule at each sodium site, and that unspecific binding of TTX does not cause serious errors, these results suggest that in 1 mum(2) of nerve membrane the number of sodium sites is 75 for rabbit, 49 for crab, and 36 for lobster nerve. PMID:5575342

  14. Detergent-free Decellularized Nerve Grafts for Long-gap Peripheral Nerve Reconstruction

    PubMed Central

    Vasudevan, Srikanth; Huang, Jiying; Botterman, Barry; Matloub, Hani S.; Keefer, Edward

    2014-01-01

    Background: Long-gap peripheral nerve defects arising from tumor, trauma, or birth-related injuries requiring nerve reconstruction are currently treated using nerve autografts and nerve allografts. Autografts are associated with limited supply and donor-site morbidity. Allografts require administration of transient immunosuppressants, which has substantial associated risks. To overcome these limitations, we investigated the use of detergent-free decellularized nerve grafts to reconstruct long-gap nerve defects in a rodent model and compared it with existing detergent processing techniques. Methods: Nerve grafts were harvested from the sciatic nerves of 9 donor rats. Twenty-four recipient rats were divided into 4 groups (6 animals per group): (1) nerve grafts (NG, positive control), (2) detergent-free decellularized (DFD) grafts, (3) detergent decellularized grafts, and (4) silicone tube conduits (negative control). Each recipient rat had a 3.5-cm graft or conduit sutured across a sciatic nerve transection injury. All animals were harvested at 12 weeks postimplantation for functional muscle analysis and nerve histomorphometry. Results: Histomorphometry results indicated maximum growth in NG when compared with other groups. DFD and detergent decellularized groups showed comparable regeneration at 12 weeks. Silicone tube group showed no regeneration as expected. Muscle force data indicated functional recovery in NG and DFD groups only. Conclusions: This study describes a detergent-free nerve decellularization technique for reconstruction of long-gap nerve injuries. We compared DFD grafts with an established detergent processing technique and found that DFD nerve grafts are successful in promoting regeneration across long-gap peripheral nerve defects as an alternative to existing strategies. PMID:25426384

  15. Microleakage of root restorations.

    PubMed

    Wenner, K K; Fairhurst, C W; Morris, C F; Hawkins, I K; Ringle, R D

    1988-12-01

    This study evaluated the microleakage of various restorative materials placed in root surfaces. A minimum of 20 freshly extracted single-rooted teeth were used for each combination of restorative materials. Four preparations were made on the root surface and each restored with a different material. After thermocycling in dye, the root was cut transversely in several sections through the restoration, and microscopically examined to record the microleakage at the interface between restorative materials and tooth. Results indicated that fewer composite resin specimens allowed microleakage into dentin as compared with either amalgam or glass ionomer materials. PMID:3060508

  16. Immediate versus delayed primary nerve repair in the rabbit sciatic nerve

    PubMed Central

    Piskin, Ahmet; Altunkaynak, Berrin Zühal; Ç?tlak, Atilla; Sezgin, Hicabi; Yaz?c?, Ozgür; Kaplan, Süleyman

    2013-01-01

    It is well known that peripheral nerve injury should be treated immediately in the clinic, but in some instances, repair can be delayed. This study investigated the effects of immediate versus delayed (3 days after injury) neurorrhaphy on repair of transected sciatic nerve in New Zealand rabbits using stereological, histomorphological and biomechanical methods. At 8 weeks after immediate and delayed neurorrhaphy, axon number and area in the sciatic nerve, myelin sheath and epineurium thickness, Schwann cell morphology, and the mechanical property of nerve fibers did not differ obviously. These results indicate that delayed neurorrhaphy do not produce any deleterious effect on sciatic nerve repair. PMID:25206663

  17. Immediate versus delayed primary nerve repair in the rabbit sciatic nerve.

    PubMed

    Piskin, Ahmet; Altunkaynak, Berrin Zühal; Çitlak, Atilla; Sezgin, Hicabi; Yaz?c?, Ozgür; Kaplan, Süleyman

    2013-12-25

    It is well known that peripheral nerve injury should be treated immediately in the clinic, but in some instances, repair can be delayed. This study investigated the effects of immediate versus delayed (3 days after injury) neurorrhaphy on repair of transected sciatic nerve in New Zealand rabbits using stereological, histomorphological and biomechanical methods. At 8 weeks after immediate and delayed neurorrhaphy, axon number and area in the sciatic nerve, myelin sheath and epineurium thickness, Schwann cell morphology, and the mechanical property of nerve fibers did not differ obviously. These results indicate that delayed neurorrhaphy do not produce any deleterious effect on sciatic nerve repair. PMID:25206663

  18. Effectively Axonal-supercharged Interpositional Jump-Graft with an Artificial Nerve Conduit for Rat Facial Nerve Paralysis

    PubMed Central

    Niimi, Yosuke; Takeuchi, Yuichi; Sasaki, Ryo; Watanabe, Yorikatsu; Yamato, Masayuki; Miyata, Mariko; Sakurai, Hiroyuki

    2015-01-01

    Background: Interpositional jump graft (IPJG) is a nerve graft axonally supercharged from the hypoglossal nerve. However, for using the technique, an autologous nerve, which should contain the great auricular and sural nerves, must be obtained. Depending on the donor site, unavoidable issues such as nerve disorders and postoperative scarring may appear. To reduce the issues, in this study, the authors developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit and investigated the efficacy of an IPJG with an artificial nerve conduit in a rat facial nerve paresis model. Methods: A ligature clip was used to crush the facial nerve trunk, thereby creating a partial facial nerve paresis model. An artificial nerve conduit was then prepared with a 10-mm-long silicone tube containing 10 ?L type I collagen and used to create an IPJG between the facial nerve trunk and the hypoglossal nerve (the silicone tube group). Thirteen weeks after the surgery, the outcome was histologically and physiologically compared with conventional IPJG with autograft using the great auricular nerve. Results: Retrograde tracer test confirmed a double innervation by the facial and hypoglossal nerve nuclei. In the autograft and silicone tube groups, the regeneration of myelinated axons was observed. Conclusion: In this study, the authors successfully developed an end-to-side neurorrhaphy technique with the recipient nerve and an artificial nerve conduit, and revealed that an IPJG in the conduit was effective in the rat facial nerve paresis model. PMID:26180717

  19. Hypothermic preservation of peripheral nerve grafts: A histomorphometric study

    Microsoft Academic Search

    Akihito Tsujino; Koichiro Hayashi; Isao Koshima

    1996-01-01

    Nerve preservation is essential for peripheral nerve grafting. We studied nerve regeneration in autografts preserved under\\u000a hypothermic conditions. Twenty-mm sciatic nerve segments were resected from Lewis rats and preserved at 4C for 0 to 48h,\\u000a the duration of preservation being increased in 12-h increments. These nerve segments were then transplanted to syngeneic\\u000a rats. At 15 weeks, the recipient sciatic nerves

  20. Carbon dioxide laser-assisted nerve repair: effect of solder and suture material on nerve regeneration in rat sciatic nerve.

    PubMed

    Menovsky, Tomas; Beek, Johan F

    2003-01-01

    In order to further improve and explore the role of lasers for nerve reconstruction, this study was designed to investigate regeneration of sharply transected peripheral nerves repaired with a CO(2) milliwatt laser in combination with three different suture materials and a bovine albumin protein solder as an adjunct to the welding process. Unilateral sciatic nerve repair was performed in 44 rats. In the laser group, nerves were gently apposed, and two stay sutures (10-0 nylon, 10-0 polyglycolic acid, or 25 microm stainless steel) were placed epi/perineurially. Thereafter, the repair site was fused at 100 mW with pulses of 1.0 s. In the subgroup of laser-assisted nerve repair (LANR), albumen was used as a soldering agent to further reinforce the repair site. The control group consisted of nerves repaired by conventional microsurgical suture repair (CMSR), using 4-6 10-0 nylon sutures. Evaluation was performed at 1 and 6 weeks after surgery, and included qualitative and semiquantitative light microscopy. LANR performed with a protein solder results in a good early peripheral nerve regeneration, with an optimal alignment of nerve fibers and minimal connective tissue proliferation at the repair site. All three suture materials produced a foreign body reaction; the least severe was with polyglycolic acid sutures. CMSR resulted in more pronounced foreign-body granulomas at the repair site, with more connective-tissue proliferation and axonal misalignment. Furthermore, axonal regeneration in the distal nerve segment was better in the laser groups. Based on these results, CO(2) laser-assisted nerve repair with soldering in combination with absorbable sutures has the potential of allowing healing to occur with the least foreign-body reaction at the repair site. Further experiments using this combination are in progress. PMID:12740882

  1. Treatment of a crown-root fracture with concomitant root fracture.

    PubMed

    Feierabend, Stefanie; Jockel-Schneider, Yvonne; Klaiber, Bernd

    2011-03-01

    The aim of this case report was to present a treatment strategy for severely injured teeth in children and adolescents by using periodontal surgery and adhesive techniques. A 16-year-old boy presented after a severe bicycle accident. A radiograph revealed a root fracture with connective tissue healing and displacement. Clinically, a crown-root fracture as well as an uncomplicated crown fracture of the same fragment was obvious. The root canal was prepared and filled with gutta-percha to the fracture line. A full periodontal flap was performed, and the crown-root fragment was adhesively fixed. The flap was tightly apposed, and the missing mesial edge of the tooth was restored with composite resin. A control radiograph showed a neatly fixed coronal fragment and sufficient root canal filling. The amount of work required proved to be acceptable for both patient and clinician--even if an implantation might have to be considered when the patient is full-grown--because of the longevity of the procedure. PMID:21465011

  2. Effects of Fault Displacement on Emplacement Drifts

    SciTech Connect

    F. Duan

    2000-04-25

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10{sup -5} adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M&O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure.

  3. Central projections of the lateral line nerves in the shovelnose sturgeon.

    PubMed

    New, J G; Northcutt, R G

    1984-05-01

    Primary projections of the anterior ( ALLN ) and posterior ( PLLN ) lateral line nerves were traced in the shovelnose sturgeon by means of horseradish peroxidase (HRP) histochemistry and silver degeneration. The trunk of the ALLN divides into dorsal and ventral roots as it enters the medulla. Fibers of the dorsal root form ascending and descending branches that terminate within the ipsilateral dorsal octavolateralis nucleus and the dorsal granular component of the lateral eminentia granularis. Fibers of the ventral root of the ALLN , as well as fibers of the PLLN , enter the medulla ventral to the dorsal root of the ALLN where some of the fibers terminate among the dendrites of the magnocellular octaval nucleus. The bulk of the fibers form ascending and descending branches that terminate within the ipsilateral medial octavolateralis nucleus. A portion of the ascending fibers continue more rostrally and terminate in the ipsilateral eminentia granularis and bilaterally in the cerebellar corpus. Some fibers of the descending rami of both the ALLN and PLLN extend beyond the caudal limit of the medial octavolateralis nucleus to terminate in the caudal octavolateralis nucleus. The HRP cases also revealed retrogradely filled large neurons whose axons course peripherally in the lateral line nerve and are likely efferent to the lateral line organs. PMID:6725636

  4. Nerve injury induces a new profile of tactile and mechanical nociceptor input from undamaged peripheral afferents.

    PubMed

    Boada, M Danilo; Gutierrez, Silvia; Aschenbrenner, Carol A; Houle, Timothy T; Hayashida, Ken-Ichiro; Ririe, Douglas G; Eisenach, James C

    2015-01-01

    Chronic pain after nerve injury is often accompanied by hypersensitivity to mechanical stimuli, yet whether this reflects altered input, altered processing, or both remains unclear. Spinal nerve ligation or transection results in hypersensitivity to mechanical stimuli in skin innervated by adjacent dorsal root ganglia, but no previous study has quantified the changes in receptive field properties of these neurons in vivo. To address this, we recorded intracellularly from L4 dorsal root ganglion neurons of anesthetized young adult rats, 1 wk after L5 partial spinal nerve ligation (pSNL) or sham surgery. One week after pSNL, hindpaw mechanical withdrawal threshold in awake, freely behaving animals was decreased in the L4 distribution on the nerve-injured side compared with sham controls. Electrophysiology revealed that high-threshold mechanoreceptive cells of A-fiber conduction velocity in L4 were sensitized, with a seven-fold reduction in mechanical threshold, a seven-fold increase in receptive field area, and doubling of maximum instantaneous frequency in response to peripheral stimuli, accompanied by reductions in after-hyperpolarization amplitude and duration. Only a reduction in mechanical threshold (minimum von Frey hair producing neuronal activity) was observed in C-fiber conduction velocity high-threshold mechanoreceptive cells. In contrast, low-threshold mechanoreceptive cells were desensitized, with a 13-fold increase in mechanical threshold, a 60% reduction in receptive field area, and a 40% reduction in instantaneous frequency to stimulation. No spontaneous activity was observed in L4 ganglia, and the likelihood of recording from neurons without a mechanical receptive field was increased after pSNL. These data suggest massively altered input from undamaged sensory afferents innervating areas of hypersensitivity after nerve injury, with reduced tactile and increased nociceptive afferent response. These findings differ importantly from previous preclinical studies, but are consistent with clinical findings in most patients with chronic neuropathic pain. PMID:25274350

  5. Displacement based multilevel structural optimization

    NASA Technical Reports Server (NTRS)

    Striz, Alfred G.

    1995-01-01

    Multidisciplinary design optimization (MDO) is expected to play a major role in the competitive transportation industries of tomorrow, i.e., in the design of aircraft and spacecraft, of high speed trains, boats, and automobiles. All of these vehicles require maximum performance at minimum weight to keep fuel consumption low and conserve resources. Here, MDO can deliver mathematically based design tools to create systems with optimum performance subject to the constraints of disciplines such as structures, aerodynamics, controls, etc. Although some applications of MDO are beginning to surface, the key to a widespread use of this technology lies in the improvement of its efficiency. This aspect is investigated here for the MDO subset of structural optimization, i.e., for the weight minimization of a given structure under size, strength, and displacement constraints. Specifically, finite element based multilevel optimization of structures (here, statically indeterminate trusses and beams for proof of concept) is performed. In the system level optimization, the design variables are the coefficients of assumed displacement functions, and the load unbalance resulting from the solution of the stiffness equations is minimized. Constraints are placed on the deflection amplitudes and the weight of the structure. In the subsystems level optimizations, the weight of each element is minimized under the action of stress constraints, with the cross sectional dimensions as design variables. This approach is expected to prove very efficient, especially for complex structures, since the design task is broken down into a large number of small and efficiently handled subtasks, each with only a small number of variables. This partitioning will also allow for the use of parallel computing, first, by sending the system and subsystems level computations to two different processors, ultimately, by performing all subsystems level optimizations in a massively parallel manner on separate processors. It is expected that the subsystems level optimizations can be further improved through the use of controlled growth, a method which reduces an optimization to a more efficient analysis with only a slight degradation in accuracy. The efficiency of all proposed techniques is being evaluated relative to the performance of the standard single level optimization approach where the complete structure is weight minimized under the action of all given constraints by one processor and to the performance of simultaneous analysis and design which combines analysis and optimization into a single step. It is expected that the present approach can be expanded to include additional structural constraints (buckling, free and forced vibration, etc.) or other disciplines (passive and active controls, aerodynamics, etc.) for true MDO.

  6. Communications Between the Trigeminal Nerve and the Facial Nerve in the Face: A Systematic Review.

    PubMed

    Hwang, Kun; Yang, Su Cheol; Song, Ju Sung

    2015-07-01

    The aim of the article is to elucidate the communications between the trigeminal nerve and facial nerve in the face. In a PubMed search, 328 studies were found using the terms 'trigeminal nerve, facial nerve, and communication.' The abstracts were read and 39 full-text articles were reviewed. Among them, 11 articles were analyzed.In the studies using dissection, the maxillary branch (V2) had the highest frequency (95.0%?±?8.0%) of communication with the facial nerve, followed by the mandibular branch (V3) (76.7%?±?38.5%). The ophthalmic branch (V1) had the lowest frequency of communication (33.8%?±?19.5%). In a Sihler stain, all of the maxillary branches and mandibular branches had communications with the facial nerve and 85.7% (12/14 hemifaces) of the ophthalmic branches had communications. The frequency of communications between the trigeminal nerve and facial nerve were significantly higher (P?=?0.00, t-test) in the studies using a Sihler stain (94.7%?±?1.1%) than the studies using dissection (76.9?±?35.8).The reason for the significantly higher frequency of trigeminal-facial communication in the studies using a Sihler stain is because of the limitation of the Sihler stain itself. This technique cannot differentiate the motor nerves from sensory nerves at the periphery, and a crossover can be misinterpreted as communication near to nerve terminal. PMID:26114519

  7. Stem cell salvage of injured peripheral nerve.

    PubMed

    Grimoldi, Nadia; Colleoni, Federica; Tiberio, Francesca; Vetrano, Ignazio G; Cappellari, Alberto; Costa, Antonella; Belicchi, Marzia; Razini, Paola; Giordano, Rosaria; Spagnoli, Diego; Pluderi, Mauro; Gatti, Stefano; Morbin, Michela; Gaini, Sergio M; Rebulla, Paolo; Bresolin, Nereo; Torrente, Yvan

    2015-01-01

    We previously developed a collagen tube filled with autologous skin-derived stem cells (SDSCs) for bridging long rat sciatic nerve gaps. Here we present a case report describing a compassionate use of this graft for repairing the polyinjured motor and sensory nerves of the upper arms of a patient. Preclinical assessment was performed with collagen/SDSC implantation in rats after sectioning the sciatic nerve. For the patient, during the 3-year follow-up period, functional recovery of injured median and ulnar nerves was assessed by pinch gauge test and static two-point discrimination and touch test with monofilaments, along with electrophysiological and MRI examinations. Preclinical experiments in rats revealed rescue of sciatic nerve and no side effects of patient-derived SDSC transplantation (30 and 180 days of treatment). In the patient treatment, motor and sensory functions of the median nerve demonstrated ongoing recovery postimplantation during the follow-up period. The results indicate that the collagen/SDSC artificial nerve graft could be used for surgical repair of larger defects in major lesions of peripheral nerves, increasing patient quality of life by saving the upper arms from amputation. PMID:24268028

  8. Ancient schwannoma of vagus nerve mimicking hamartoma.

    PubMed

    Kundu, Susmita; Biswas, Debabani; Misra, Swapnendu; Dutta, Shantanu; Sen, Annoy

    2014-01-01

    Schwannomas arising from vagus nerve sheath are rare mediastinal neurogenic tumours. Schwannomas usually arise from left hemithorax. Unlike a hamartoma, radiologically, calcification is rarely seen in schwannomas. We present the rare case of an ancient schwannoma arising from vagus nerve sheath from the right hemithorax presenting with gross calcification. PMID:25823116

  9. Vagus nerve stimulation for epilepsy: a review

    Microsoft Academic Search

    C. D. Binnie

    2000-01-01

    Vagus nerve stimulation is an empirically based method for treatment of epilepsy by repeated stimulation of the left vagus nerve through implanted electrodes. Despite studies in animals and man, which show changes in brain electrophysiology, metabolism and neurochemistry, the mode of action remains unknown. Clinical testing has presented methodological challenges, as it is difficult to assess under double blind conditions

  10. Radiation therapy for primary optic nerve meningiomas

    Microsoft Academic Search

    J. L. Smith; M. M. Vuksanovic; B. M. Yates; D. C. Bienfang

    1981-01-01

    Optic nerve sheath meningiomas, formerly thought to be rare, have been encountered with surprising frequency since the widespread use of computed tomography. Early diagnosis led to an enthusiastic surgical approach to these lesions, but this has been tempered by the realization that even in the best of hands, blindness followed such surgery with distressing frequency. Optic nerve sheath meningiomas may

  11. The Sheath of the Optic Nerve

    Microsoft Academic Search

    Sohan Singh Hayreh

    1984-01-01

    The sheath of the optic nerve was studied in rhesus monkeys, humans, and rabbits. The sheath (i.e., dura mater and arachnoid mater) was normally found to be loose near the eyeball, with a much bigger space between the optic nerve and the sheath than anywhere else in its course, consequently presenting bulbous appearance just behind the eyeball. The space was

  12. Ophthalmoscopic Evaluation of the Optic Nerve Head

    Microsoft Academic Search

    Jost B. Jonas; Wido M. Budde; Songhomitra Panda-Jonas

    1999-01-01

    Optic nerve diseases, such as the glaucomas, lead to changes in the intrapapillary and parapapillary region of the optic nerve head. These changes can be described by the following variables: size and shape of the optic disk; size, shape, and pallor of the neuroretinal rim; size of the optic cup in relation to the area of the disk; configuration and

  13. A Safe Lab on Nerve Gases.

    ERIC Educational Resources Information Center

    Tucker, David C.

    1988-01-01

    Describes an experiment involving pineapples and gelatin that allows students to investigate the conditions that typically render an enzyme functionless, similar to the effect of nerve gasses. Discusses the materials, procedures, and results, drawing analogies to the effects of a nerve gas. (CW)

  14. Ephaptic Coupling of Myelinated Nerve S. Binczaka

    E-print Network

    Eilbeck, Chris

    by nonlinear difference-differential equations. Called "saltatory" conduction by the electrophysiologists, 26, 27, 28, 33, 34, 36, 37, 39], saltatory conduction on myelinated nerve models introduces two and discrete limits, clarifying the nature of the conduction process on an isolated nerve axon. Since

  15. Cadaveric nerve allotransplantation in the treatment of persistent thoracic neuralgia.

    PubMed

    Barbour, John R; Yee, Andrew; Moore, Amy M; Trulock, Elbert P; Buchowski, Jacob M; Mackinnon, Susan E

    2015-04-01

    When relief from neuralgia cannot be achieved with traditional methods, neurectomy may be considered to abate the stimulus, and primary opposition of the terminal nerve ending is recommended to prevent neuroma. Nerve repair with autograft is limited by autologous nerves available for large nerve defects. Cadaveric allografts provide an unlimited graft source without donor-site morbidities, but are rapidly rejected unless appropriate immunosuppression is achieved. An optimal treatment method for nerve allograft transplantation would minimize rejection while simultaneously permitting nerve regeneration. This report details a novel experience of nerve allograft transplantation using cadaveric nerve grafts to desensitize persistent postoperative thoracic neuralgia. PMID:25841822

  16. Nerve-sparing schwannoma removal from two infrequent origins.

    PubMed

    Inzirillo, Francesco; Giorgetta, Casimiro; Ravalli, Eugenio

    2015-05-01

    Schwannomas of nerve sheath origin (Schwann cell) are the most common neurogenic thoracic tumors and they usually originate from an intercostal nerve, especially in the paravertebral region. Tumors that originate from other nerves such as the phrenic nerve, vagus, or sympathetic nerves are uncommon. We report two cases of schwannomas in rare locations. A 62-year-old woman had a giant schwannoma arising from the right phrenic nerve, and a 57-year-old woman had one from the left sympathetic nerve. Both tumors were completely removed with preservation of the nerves. PMID:24939915

  17. The effects of repetitive compression on nerve conduction and blood flow in the rabbit sciatic nerve.

    PubMed

    Yoshii, Y; Nishiura, Y; Terui, N; Hara, Y; Saijilafu; Ochiai, Naoyuki

    2010-05-01

    The objective of this study was to clarify the effect of repetitive compression on nerve physiology in an experimental rabbit model. We defined 80 mmHg as a compression force which caused temporary disturbance of nerve conduction and blood flow with a brief compression. The following compressions were applied for 30 minutes to rabbit sciatic nerves: continuous compression, low frequency release compression (1 second of release time every 30 seconds) and high frequency release compression (1 second of release time every 10 seconds). Compound nerve action potentials and nerve blood flow were evaluated from the start of compression until 30 minutes after release. Endoneurial microvascular permeability was evaluated with Evans Blue albumin. The repetitive compression groups showed delay in recovery of compound nerve action potentials and blood flow after release, with endoneurial oedema. These findings suggest that repetitive compression may increase the risk of breakdown of the blood nerve barrier. PMID:20444785

  18. Antibiotics as low-molecular-mass displacers in ion-exchange displacement chromatography

    Microsoft Academic Search

    Amitava Kundu; Suresh Vunnum; Steven M. Cramer

    1995-01-01

    While the ability to carry out simultaneous concentration and purification in a single displacement step has significant advantages for downstream processing of pharmaceuticals, a major impediment to the implementtion of displacement chromatography has been the lack of suitable displacer compounds. An important recent advance in the state-of-the-art of displacement chromatography has been the discovery that low-molecular-mass dendritic polymers and protected

  19. Recombinant human nerve growth factor is biologically active and labels novel high-affinity binding sites in rat brain

    Microsoft Academic Search

    C. A. Altar; L. E. Burton; G. L. Bennett; M. Dugich-Djordjevic

    1991-01-01

    Iodinated recombinant human nerve growth factor (125I-rhNGF) stimulated neurite formation in PC12 cell cultures with a half-maximal potency of 35-49 pg\\/ml, compared with 39-52 pg\\/ml for rhNGF. In quantitative ligand autoradiography, the in vitro equilibrium binding of 125I-rhNGF to brain sections showed a 10-fold regional variation in density and was saturable, reversible, and specifically displaced by up to 74% with

  20. Recombinant Human Nerve Growth Factor is Biologically Active and Labels Novel High-Affinity Binding Sites in Rat Brain

    Microsoft Academic Search

    C. Anthony Altar; Louis E. Burton; Gregory L. Bennett; Millicent Dugich-Djordjevic

    1991-01-01

    Iodinated recombinant human nerve growth factor (125I-rhNGF) stimulated neurite formation in PC12 cell cultures with a half-maximal potency of 35-49 pg\\/ml, compared with 39-52 pg\\/ml for rhNGF. In quantitative ligand autoradiography, the in vitro equilibrium binding of 125I-rhNGF to brain sections showed a 10-fold regional variation in density and was saturable, reversible, and specifically displaced by up to 74% with

  1. Scaling up digital circuit computation with DNA strand displacement cascades.

    PubMed

    Qian, Lulu; Winfree, Erik

    2011-06-01

    To construct sophisticated biochemical circuits from scratch, one needs to understand how simple the building blocks can be and how robustly such circuits can scale up. Using a simple DNA reaction mechanism based on a reversible strand displacement process, we experimentally demonstrated several digital logic circuits, culminating in a four-bit square-root circuit that comprises 130 DNA strands. These multilayer circuits include thresholding and catalysis within every logical operation to perform digital signal restoration, which enables fast and reliable function in large circuits with roughly constant switching time and linear signal propagation delays. The design naturally incorporates other crucial elements for large-scale circuitry, such as general debugging tools, parallel circuit preparation, and an abstraction hierarchy supported by an automated circuit compiler. PMID:21636773

  2. Peripheral nerve morphogenesis induced by scaffold micropatterning

    PubMed Central

    Memon, Danish; Boneschi, Filippo Martinelli; Madaghiele, Marta; Brambilla, Paola; Del Carro, Ubaldo; Taveggia, Carla; Riva, Nilo; Trimarco, Amelia; Lopez, Ignazio D.; Comi, Giancarlo; Pluchino, Stefano; Martino, Gianvito; Sannino, Alessandro; Quattrini, Angelo

    2014-01-01

    Several bioengineering approaches have been proposed for peripheral nervous system repair, with limited results and still open questions about the underlying molecular mechanisms. We assessed the biological processes that occur after the implantation of collagen scaffold with a peculiar porous microstructure of the wall in a rat sciatic nerve transection model compared to commercial collagen conduits and nerve crush injury using functional, histological and genome wide analyses. We demonstrated that within 60 days, our conduit had been completely substituted by a normal nerve. Gene expression analysis documented a precise sequential regulation of known genes involved in angiogenesis, Schwann cells/axons interactions and myelination, together with a selective modulation of key biological pathways for nerve morphogenesis induced by porous matrices. These data suggest that the scaffold’s microstructure profoundly influences cell behaviors and creates an instructive micro-environment to enhance nerve morphogenesis that can be exploited to improve recovery and understand the molecular differences between repair and regeneration. PMID:24559639

  3. On the terminology of cranial nerves.

    PubMed

    Simon, František; Mare?ková-Štolcová, Elena; Pá?, Libor

    2011-10-20

    The present contribution adopts various points of view to discuss the terminology of the twelve nervi craniales. These are paired nerves and have dual names, terms with Roman ordinal numerals, i.e., the nerves are numbered in the top-to-bottom direction, and descriptive historical names. The time of origin and motivation behind the investigated terms are determined. The majority of terms come from the 17th and 18th centuries. The motivation behind most of them is (a) nerve localization, as this is in conformity with anatomical nomenclature in general, (b) nerve function, and rarely (c) nerve appearance. The occurrence of synonymous names and variants is also a focus of attention. In several cases, reference is made to the process called terminologization, meaning when a certain expression acquires technical meaning and the characteristic/feature of the term. PMID:21724380

  4. Using a 2D displacement sensor to derive 3D displacement information

    NASA Technical Reports Server (NTRS)

    Soares, Schubert F. (Inventor)

    2002-01-01

    A 2D displacement sensor is used to measure displacement in three dimensions. For example, the sensor can be used in conjunction with a pulse-modulated or frequency-modulated laser beam to measure displacement caused by deformation of an antenna on which the sensor is mounted.

  5. Sympathetic nerve fibers and ganglia in canine cervical vagus nerves: Localization and quantitation

    PubMed Central

    Onkka, Patrick; Maskoun, Waddah; Rhee, Kyoung-Suk; Hellyer, Jessica; Patel, Jheel; Tan, Jian; Chen, Lan S.; Vinters, Harry V.; Fishbein, Michael C.; Chen, Peng-Sheng

    2013-01-01

    Background Cervical vagal nerve (CVN) stimulation may improve left ventricular ejection fraction in patients with heart failure. Objectives To test the hypothesis that sympathetic structures are present in the CVN and to describe the location and quantitate these sympathetic components of the CVN. Methods We performed immunohistochemical studies of the CVN from 11 normal dogs and simultaneously recorded stellate ganglion nerve activity, left thoracic vagal nerve activity, and subcutaneous electrocardiogram in 2 additional dogs. Results A total of 28 individual nerve bundles were present in the CVNs of the first 11 dogs, with an average of 1.87 ± 1.06 per dog. All CVNs contain tyrosine hydroxylase-positive (sympathetic) nerves, with a total cross-sectional area of 0.97 ± 0.38 mm2. The sympathetic nerves were nonmyelinated, typically located at the periphery of the nerve bundles and occupied 0.03%–2.80% of the CVN cross-sectional area. Cholineacetyltransferase-positive nerve fibers occupied 12.90%–42.86% of the CVN cross-sectional areas. Ten of 11 CVNs showed tyrosine hydroxylase and cholineacetyltransferase colocalization. In 2 dogs with nerve recordings, we documented heart rate acceleration during spontaneous vagal nerve activity in the absence of stellate ganglion nerve activity. Conclusions Sympathetic nerve fibers are invariably present in the CVNs of normal dogs and occupy in average up to 2.8% of the cross-sectional area. Because sympathetic nerve fibers are present in the periphery of the CVNs, they may be susceptible to activation by electrical stimulation. Spontaneous activation of the sympathetic component of the vagal nerve may accelerate the heart rate. PMID:23246597

  6. THE DISPLACEMENTS OF ANCHORED DIAPHRAGM WALLS

    Microsoft Academic Search

    ANNA SIEMI?SKA-LEWANDOWSKA

    Due to the influence of the engineering works on buildings in the vicinity of deep excava- tions, two large Warsaw underground stations were constantly monitored. The results of measurements of the displacements of diaphragm walls are presented. Assessment of displacements was carried out on the basis of high-precision land surveying of fixed points positioned on diaphragm walls. The conclu- sions

  7. Displacements, Strains, and Tilts at Teleseismic Distances

    Microsoft Academic Search

    1965-01-01

    The dislocation theory representation of faulting of Vvedenskaya, Steketee, Chin- nery, and Maruyama is used to compute the residual displacement, strain, and tilt fields at intermediate and large distances from major earthquakes. It is shown that the distant fields are large enough to be detected by modern instruments. The vertical displacement field from the Alaskan earthquake of March 27, 1964,

  8. Video Games, Adolescents, and the Displacement Effect

    ERIC Educational Resources Information Center

    Fisher, Carla Christine

    2012-01-01

    The displacement effect (the idea that time spent in one activity displaces time spent in other activities) was examined within the lens of adolescents' video game use and their time spent reading, doing homework, in physically active sports and activities, in creative play, and with parents and friends. Data were drawn from the Panel Study…

  9. Young Children's Understanding of Displaced Aggression.

    ERIC Educational Resources Information Center

    Weiss, Michael G.; Miller, Patricia H.

    1983-01-01

    Examines early phases of understanding of causes of moderately and extremely displaced aggression. Preschool and kindergarten children three to five years of age viewed eight videotaped episodes of displaced aggression. Comprehension was assessed by means of open-ended questions and forced-choice picture selections. (Author/RH)

  10. Displaced Homemakers: Vo-Tech Workshop Guide.

    ERIC Educational Resources Information Center

    Peltier, Wanda Jo

    Written for displaced homemaker programs in vocational-technical schools, this curriculum contains material designed so that instructors can prepare student manuals appropriate to almost any educational support situation for displaced homemakers. An overview provides information on special needs groups, curriculum use, and resources and sample…

  11. Displacement fields from point cloud data: Application of particle imaging velocimetry to landslide geodesy

    NASA Astrophysics Data System (ADS)

    Aryal, Arjun; Brooks, Benjamin A.; Reid, Mark E.; Bawden, Gerald W.; Pawlak, Geno R.

    2012-03-01

    Acquiring spatially continuous ground-surface displacement fields from Terrestrial Laser Scanners (TLS) will allow better understanding of the physical processes governing landslide motion at detailed spatial and temporal scales. Problems arise, however, when estimating continuous displacement fields from TLS point-clouds because reflecting points from sequential scans of moving ground are not defined uniquely, thus repeat TLS surveys typically do not track individual reflectors. Here, we implemented the cross-correlation-based Particle Image Velocimetry (PIV) method to derive a surface deformation field using TLS point-cloud data. We estimated associated errors using the shape of the cross-correlation function and tested the method's performance with synthetic displacements applied to a TLS point cloud. We applied the method to the toe of the episodically active Cleveland Corral Landslide in northern California using TLS data acquired in June 2005-January 2007 and January-May 2010. Estimated displacements ranged from decimeters to several meters and they agreed well with independent measurements at better than 9% root mean squared (RMS) error. For each of the time periods, the method provided a smooth, nearly continuous displacement field that coincides with independently mapped boundaries of the slide and permits further kinematic and mechanical inference. For the 2010 data set, for instance, the PIV-derived displacement field identified a diffuse zone of displacement that preceded by over a month the development of a new lateral shear zone. Additionally, the upslope and downslope displacement gradients delineated by the dense PIV field elucidated the non-rigid behavior of the slide.

  12. Multifunctional Silk Nerve Guides for Axon Outgrowth

    NASA Astrophysics Data System (ADS)

    Tupaj, Marie C.

    Peripheral nerve regeneration is a critical issue as 2.8% of trauma patients present with this type of injury, estimating a total of 200,000 nerve repair procedures yearly in the United States. While the peripheral nervous system exhibits slow regeneration, at a rate of 0.5 mm -- 9 mm/day following trauma, this regenerative ability is only possible under certain conditions. Clinical repairs have changed slightly in the last 30 years and standard methods of treatment include suturing damaged nerve ends, allografting, and autografting, with the autograft the gold standard of these approaches. Unfortunately, the use of autografts requires a second surgery and there is a shortage of nerves available for grafting. Allografts are a second option however allografts have lower success rates and are accompanied by the need of immunosuppressant drugs. Recently there has been a focus on developing nerve guides as an "off the shelf" approach. Although some natural and synthetic guidance channels have been approved by the FDA, these nerve guides are unfunctionalized and repair only short gaps, less than 3 cm in length. The goal of this project was to identify strategies for functionalizing peripheral nerve conduits for the outgrowth of neuron axons in vitro . To accomplish this, two strategies (bioelectrical and biophysical) were indentified for increasing axon outgrowth and promoting axon guidance. Bioelectrical strategies exploited electrical stimulation for increasing neurite outgrowth. Biophysical strategies tested a range of surface topographies for axon guidance. Novel methods were developed for integrating electrical and biophysical strategies into silk films in 2D. Finally, a functionalized nerve conduit system was developed that integrated all strategies for the purpose of attaching, elongating, and guiding nervous tissue in vitro. Future directions of this work include silk conduit translation into a rat sciatic nerve model in vivo for the purpose of repairing long (> 3 cm) peripheral nerve gaps.

  13. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  14. Root numbers of curves

    Microsoft Academic Search

    MARIA SABITOVA

    2004-01-01

    We generalize a theorem of D. Rohrlich concerning root numbers of elliptic curves over the field of rational numbers. Our result applies to curves of all higher genera over number fields. Namely, under certain conditions which naturally extend the conditions used by D. Rohrlich, we show that the root number associated to a smooth projective curve over a number field

  15. Use of tubes in peripheral nerve repair.

    PubMed

    Dahlin, L B; Lundborg, G

    2001-04-01

    The use of tubes as an alternative to primary nerve suture in fresh nerve transections has been introduced as a biologic approach to nerve injuries, creating optimal conditions for axonal regeneration over a short empty space intentionally created between the proximal and distal nerve ends. The idea may seem controversial and has been criticized using the arguments that silicone in itself may create problems like inflammation and the tube may compress the nerve ends. With the use of appropriately sized tubes for bridging a maximum 5-mm gap in human median and ulnar nerves, the authors have found the technique to be useful and persistent at follow-up examinations for up to 4 to 5 years. In addition, from the intellectual point of view, the principle illustrates the concept by which emphasis is placed on the intrinsic healing capacities of the nerve rather than on the technical skill of the surgeon. The thin mesothelial lining found around the silicone tube lacks primary inflammatory signs at follow-up after 1 year, and no signs of compression are seen. It may be an advantage because it allows sliding of the repair site against the surrounding tissues. Tubes made of bioresorbable material may seem ideal, but they may introduce new problems associated with the resorption process in terms of a substantial unrestricted macrophage invasion, fibrosis, and disorganized axonal growth. For an extended nerve defect, the use of autologous nerve grafts is still the gold standard, because no tubular conduit or other conduit has so far proved equal to autologous nerve grafts, at least not for reconstruction of human median and ulnar nerve trunks. Alternatives other than tubes are currently being developed and investigated. For the future, the use of tubes for repair and reconstruction of nerves may have interesting potentials, because such a structure allows several types of tissue engineering. Various matrices containing, for instance, appropriate cells, factors, or other stimulating agents can be introduced in the tube lumen and can also be incorporated in a slow-release form in the walls of the tube and manipulated. Cultured Schwann cells or other cellular components, with or without manipulated production machinery, are probably the cells of choice for introduction in the tubes. Tubes may thus prove to be interesting alternatives to conventional repair techniques for primary repair of nerves and for reconstruction of segmental defects and for neuroma treatment in the future. PMID:11525212

  16. [Repair of peripheral nerve effect by direct suture after elongation of nerve by traction].

    PubMed

    Wang, S; Wang, H; Chen, J

    1998-05-01

    To find new technique for repair of peripheral nerve defect, the nerve elongation repair technique was adopted. Two cases with nerve defect were treated by this method. One was a 12 year old male, the defect length of right radial nerve was 7.2 cm at the elbow. The other one was a 28 year old male, the defect length of left ulnar nerve the was 5 cm at elbow. In this method, the nerve was elongated by slow stretch from distal and proximal end of the ruptured nerve. After a few days, the nerve was repaired by direct suture. After operation, the function of nerves were recovered in 119 days and 114 days respectively. Follow-up for 5 years, the function of the effected limbs were recovered to the normal side. It was concluded that: (1) the peripheral never can be elongated by slow stretch; (2) to stretch the nerve end in a rubber tube can prevent adhesion and connective tissue blocking; (3) strength and supporting point of stretching should be designed carefully. PMID:10437049

  17. Using Eggshell Membrane as Nerve Guide Channels in Peripheral Nerve Regeneration

    PubMed Central

    Farjah, Gholam Hossein; Heshmatian, Behnam; Karimipour, Mojtaba; Saberi, Ali

    2013-01-01

    Objective(s): The aim of this study was to evaluate the final outcome of nerve regeneration across the eggsell membrane (ESM) tube conduit in comparison with autograft. Materials and Methods: Thirty adult male rats (250-300 g) were randomized into (1) ESM conduit, (2) autograft, and (3) sham surgery groups. The eggs submerged in 5% acetic acid. The decalcifying membranes were cut into four pieces, rotated over the teflon mandrel and dried at 37°C. The left sciatic nerve was surgically cut. A 10-mm nerve segment was cut and removed. In the ESM group, the proximal and distal cut ends of the sciatic nerve were telescoped into the nerve guides. In the autograft group, the 10 mm nerve segment was reversed and used as an autologous nerve graft. All animals were evaluated by sciatic functional index (SFI) and electrophysiology testing. Results: The improvement in SFI from the first to the last evalution in ESM and autograft groups were evaluated. On days 49 and 60 post-operation, the mean SFI of ESM group was significantly greater than the autograft group (P< 0.05). On day 90, the mean nerve conduction velocity (NCV) of ESM group was greater than autograft group, although the difference was not statistically significant (P> 0.05). Conclusion: These findings demonstrate that ESM effectively enhances nerve regeneration and promotes functional recovery in injured sciatic nerve of rat. PMID:24106593

  18. The catecholaminergic nerve plexus of Holothuroidea

    PubMed Central

    Díaz-Balzac, Carlos A.; Mejías, Wigberto; Jiménez, Luis B.

    2010-01-01

    Catecholamines have been extensively reported to be present in most animal groups, including members of Echinodermata. In this study, we investigated the presence and distribution of catecholaminergic nerves in two members of the Holothuroidea, Holothuria glaberrima (Selenka, 1867) (Aspidochirotida, Holothuroidea) and Holothuria mexicana (Ludwig, 1875) (Aspidochirotida, Holothuroidea), by using induced fluorescence for catecholamines on tissue sections and immunohistochemistry with an antibody that recognizes tyrosine hydroxylase. The presence of a catecholaminergic nerve plexus similar in distribution and extension to those previously reported in other members of Echinodermata was observed. This plexus, composed of cells and fibers, is found in the ectoneural component of the echinoderm nervous system and is continuous with the circumoral nerve ring and the radial nerves, tentacular nerves, and esophageal plexus. In addition, fluorescent nerves in the tube feet are continuous with the catecholaminergic components of the radial nerve cords. This is the first comprehensive report on the presence and distribution of catecholamines in the nervous system of Holothuroidea. The continuity and distribution of the catecholaminergic plexus strengthen the notion that the catecholaminergic cells are interneurons, since these do not form part of the known sensory or motor circuits and the fluorescence is confined to organized nervous tissue. PMID:20827375

  19. The catecholaminergic nerve plexus of Holothuroidea.

    PubMed

    Díaz-Balzac, Carlos A; Mejías, Wigberto; Jiménez, Luis B; García-Arrarás, José E

    2010-05-01

    Catecholamines have been extensively reported to be present in most animal groups, including members of Echinodermata. In this study, we investigated the presence and distribution of catecholaminergic nerves in two members of the Holothuroidea, Holothuria glaberrima (Selenka, 1867) (Aspidochirotida, Holothuroidea) and Holothuria mexicana (Ludwig, 1875) (Aspidochirotida, Holothuroidea), by using induced fluorescence for catecholamines on tissue sections and immunohistochemistry with an antibody that recognizes tyrosine hydroxylase. The presence of a catecholaminergic nerve plexus similar in distribution and extension to those previously reported in other members of Echinodermata was observed. This plexus, composed of cells and fibers, is found in the ectoneural component of the echinoderm nervous system and is continuous with the circumoral nerve ring and the radial nerves, tentacular nerves, and esophageal plexus. In addition, fluorescent nerves in the tube feet are continuous with the catecholaminergic components of the radial nerve cords. This is the first comprehensive report on the presence and distribution of catecholamines in the nervous system of Holothuroidea. The continuity and distribution of the catecholaminergic plexus strengthen the notion that the catecholaminergic cells are interneurons, since these do not form part of the known sensory or motor circuits and the fluorescence is confined to organized nervous tissue. PMID:20827375

  20. Nerve repair: toward a sutureless approach.

    PubMed

    Barton, Matthew J; Morley, John W; Stoodley, Marcus A; Lauto, Antonio; Mahns, David A

    2014-10-01

    Peripheral nerve repair for complete section injuries employ reconstructive techniques that invariably require sutures in their application. Sutures are unable to seal the nerve, thus incapable of preventing leakage of important intraneural fluids from the regenerating nerve. Furthermore, sutures are technically demanding to apply for direct repairs and often induce detrimental scarring that impedes healing and functional recovery. To overcome these limitations, biocompatible and biodegradable glues have been used to seal and repair peripheral nerves. Although creating a sufficient seal, they can lack flexibility and present infection risks or cytotoxicity. Other adhesive biomaterials have recently emerged into practice that are usually based on proteins such as albumin and collagen or polysaccharides like chitosan. These adhesives form their union to nerve tissue by either photothermal (tissue welding) or photochemical (tissue bonding) activation with laser light. These biomaterial adhesives offer significant advantages over sutures, such as their capacity to unite and seal the epineurium, ease of application, reduced invasiveness and add the potential for drug delivery in situ to facilitate regeneration. This paper reviews a number of different peripheral nerve repair (or reconstructive) techniques currently used clinically and in experimental procedures for nerve injuries with or without tissue deficit. PMID:25015388

  1. Continuous Retrograde Monitoring of the Facial Nerve

    PubMed Central

    Colletti, Vittorio; Fiorino, Francesco G.

    1996-01-01

    Continuous electromyographical (EMG) monitoring of the facial nerve is widely used during acoustic tumor surgery. Mechanical stimulation of the facial nerve is capable of eliciting synchronous and asynchronous EMG responses alerting the surgeon to damaging maneuvers performed on the nerve. Mechanical stimulation, however, elicits EMG responses only when the nerve has been injured by the underlying pathology or previous surgical maneuvers, and the technique is sensitive to administration of muscular blockers. In addition, EMG is unable to furnish quantitative information about the damage. The present paper illustrates an alternative technique for intraoperative facial nerve monitoring, that is, the recording of facial nerve antidromic potentials (FNAPs). Eleven subjects operated on by acoustic neuroma surgery via a retrosigmoid approach (tumor sizes ranging from 12 to 28 mm) participated in the investigation. Bipolar electrical stimulation of the marginalis mandibulae was performed to elicit FNAPs. Stimulus intensity ranged from 2 to 6 mA with a delivery rate of 7/second. A silver-wire electrode positioned on the proximal portion of the acoustic-facial bundle was used to record action potentials. Changes in latency and amplitude of FNAPs were analyzed as a function of the main surgical steps. FNAP monitoring provided quantitative real-time information about damaging maneuvers performed on the nerve and allowed prediction of postoperative facial function. ImagesFigure 1 PMID:17170981

  2. Superior laryngeal nerve block: an anatomical study.

    PubMed

    Stockwell, M; Lozanoff, S; Lang, S A; Nyssen, J

    1995-01-01

    Superior laryngeal nerve anaesthesia is frequently used to facilitate endotracheal intubation in the awake patient. We have modified the transcutaneous approach to this nerve block to employ a short bevel needle. This improves tactile perception in performing the procedure thus simplifying identification of the correct depth of injection. This study was designed to determine the anatomical basis of superior laryngeal nerve anaesthesia and to estimate the success rate using our modified technique. At autopsy, 20 cadavers had nerve block performed substituting 0.02% methylene blue for local anaesthetic. Dissection was then performed to identify the anatomical structures stained by the simulated local anaesthetic. Additional dissections were performed in formalin-fixed cadavers. We found that the dye was injected into the paraglottic space bounded laterally by the thyrohyoid membrane and thyroid cartilage, medially by the laryngeal submucosa, caudad by the conus elasticus, cephalad by the hyoid bone, and anteriorly and posteriorly by the anterior and posterior thyrohyoid ligaments, respectively. The internal laryngeal nerve, the sensory branch of the superior laryngeal nerve, passed through this compartment and was heavily stained with simulated local anaesthetic. Resistance to the passage of the short bevel needle was provided by the lateral glossoepiglottic fold, not the thyrohyoid membrane as we had expected. Of 40 injections, 39 were deemed successful for a success rate of 97.5%. We conclude that this is a simple and highly successful technique for performing superior laryngeal nerve anaesthesia. PMID:7712327

  3. Displacement chromatography of isomers and therapeutic compounds.

    PubMed

    Qi, Yan; Huang, Junxiong

    2002-06-14

    Displacement chromatography was successfully used to separate a binary isomer mixture, epirubicin and doxorubicin, on Kromasil KR100-10 C18 250x4.6 mm I.D. (10 microm) column. Displacement parameters such as the types and the concentrations of displacer, the composition and the flow rate of the mobile phase were critically examined in this study. The displacer employed was 30 mg/ml benzethonium chloride. Loading of feed at lower initial organic level of mobile phase coupled with displacement at higher organic level was found to give efficient separation. A 30-mg amount of binary isomer mixture was separated on an analytical column. The purification of epirubicin from the closely related impurities present in raw product solution by displacement chromatography was also investigated. The purity of epirubicin required was greater than 99% with a recovery of 60%. The results have indicated that this process made good use of the high feed load, low solvent costs, and high resolution characteristics of displacement chromatography and offered the chromatographic engineer a powerful tool for the preparative purification of therapeutic compounds. PMID:12141564

  4. Repair of peripheral nerve with vein wrapping*

    PubMed Central

    LEUZZI, S.; ARMENIO, A.; LEONE, L.; DE SANTIS, V.; DI TURI, A.; ANNOSCIA, P.; BUFANO, L.; PASCONE, M.

    2014-01-01

    Objective The post–traumatic neuro-anastomosis must be protected from the surrounding environment. This barrier must be biologically inert, biodegradable, not compressing but protecting the nerve. Formation of painful neuroma is one of the major issues with neuro-anastomosis; currently there is no consensus on post-repair neuroma prevention. Aim of this study is to evaluate the efficacy of neuroanastomosis performed with venous sheath to reduce painful neuromas formation, improve the electrical conductivity of the repaired nerve, and reduce the discrepancies of the sectioned nerve stumps. Patients and methods From a trauma population of 320 patients treated in a single centre between January 2008 and December 2011, twenty-six patients were identified as having an injury to at least one of the peripheral nerves of the arm and enrolled in the study. Patients were divided into two groups. In the group A (16 patients) the end-to-end nerve suture was wrapped in a vein sheath and compared with the group B (10 patients) in which a simple end-to-end neurorrhaphy was performed. The venous segment used to cover the nerve micro-suture was harvested from the superficial veins of the forearm. The parameters analyzed were: functional recovery of motor nerves, sensitivity and pain. Results Average follow-up was 14 months (range: 12–24 months). The group A showed a more rapid motor and sensory recovery and a reduction of the painful symptoms compared to the control group (B). Conclusions The Authors demonstrated that, in their experience, the venous sheath provides a valid solution to avoid the dispersion of the nerve fibres, to prevent adherent scars and painful neuromas formation. Moreover it can compensate the different size of two nerve stumps, allowing, thereby, a more rapid functional and sensitive recovery without expensive devices. PMID:24841688

  5. Lipofuscin in human glaucomatous optic nerves.

    PubMed

    Fernandez de Castro, J P; Mullins, R F; Manea, A M; Hernandez, J; Wallen, T; Kuehn, M H

    2013-06-01

    Lipofuscin accumulation has been observed in a number of neurodegenerative diseases. We recently found that autofluorescent particles also occur in the aged human optic nerve. In this study we sought to determine the nature of these particles and their correlation with aging, age-related macular degeneration (AMD) and primary open angle glaucoma (POAG). Groups of eight optic nerves from patients diagnosed with primary open angle glaucoma, age-related macular degeneration, age-matched controls and four optic nerves derived from controls younger than 42 years were used for the study. All samples were fixed in paraformaldehyde and frozen frontal sections were prepared. Sections were analyzed with fluorescence microscopy, bright field microscopy, Sudan black staining and spectrofluorometry using a confocal laser scanning microscope. Sections were photographed and analyzed to establish the distribution, quantity, and size of the autofluorescent particles. Additionally, transmission electron microscopy was used to determine the ultrastructural location of the granules. On unstained sections under light microscopy granules are detectable as pale brown inclusions and are easily stained with oil-soluble dyes, such as Sudan black. Granules fluoresce when excited at all tested wavelengths but lose their fluorescence after staining with Sudan black. These particles are distributed throughout the axonal columns, but not in the septa, and appear to be located within the glia ensheathing optic nerve axons. The histologic properties of the granules seen in the optic nerve sections correspond to lipofuscin aggregates, a result of incomplete degradation of oxidized proteins. Our morphometric analyses indicate that overall the optic nerves from control, glaucoma, and AMD donors contain similar amounts of lipofuscin. However, optic nerves derived from donors with glaucoma contain lipofuscin particles that are larger than those observed in the age-matched control and AMD groups. Furthermore optic nerves from glaucoma donors display a smaller diameter than those from age-matched controls resulting in a higher concentration of lipofuscin in glaucomatous optic nerves. PMID:23567206

  6. Anatomy of the ilioinguinal and iliohypogastric nerves with observations of their spinal nerve contributions.

    PubMed

    Klaassen, Zachary; Marshall, Ewarld; Tubbs, R Shane; Louis, Robert G; Wartmann, Christopher T; Loukas, Marios

    2011-05-01

    Proper anesthesia and knowledge of the anatomical location of the iliohypogastric and ilioinguinal nerves is important during hernia repair and other surgical procedures. Surgical complications have also implicated these nerves, emphasizing the importance of the development of a clear topographical map for use in their identification. The aim of this study was to explore anatomical variations in the iliohypogastric and ilioinguinal nerves and relate this information to clinical situations. One hundred adult formalin fixed cadavers were dissected resulting in 200 iliohypogastric and ilioinguinal nerve specimens. Each nerve was analyzed for spinal nerve contribution and classified accordingly. All nerves were documented where they entered the abdominal wall with this point being measured in relation to the anterior superior iliac spine (ASIS). The linear course of each nerve was followed, and its lateral distance from the midline at termination was measured. The ilioinguinal nerve originated from L1 in 130 specimens (65%), from T12 and L1 in 28 (14%), from L1 and L2 in 22 (11%), and from L2 and L3 in 20 (10%). The nerve entered the abdominal wall 2.8 ± 1.1 cm medial and 4 ± 1.2 cm inferior to the ASIS and terminated 3 ± 0.5 cm lateral to the midline. The iliohypogastric nerve originated from T12 on 14 sides (7%), from T12 and L1 in 28 (14%), from L1 in 20 (10%), and from T11 and T12 in 12 (6%). The nerve entered the abdominal wall 2.8 ± 1.3 cm medial and 1.4 ± 1.2 cm inferior to the ASIS and terminated 4 ± 1.3 cm lateral to the midline. For both nerves, the distance between the ASIS and the midline was 12.2 ± 1.1 cm. To reduce nerve damage and provide sufficient anesthetic for nerve block during surgical procedures, the precise anatomical location and spinal nerve contributions of the iliohypogastric and ilioinguinal nerves need to be considered. PMID:21509811

  7. Ischaemia of peripheral nerve and muscle.

    PubMed Central

    Harriman, D G

    1977-01-01

    Although skeletal muscle and peripheral nerves are both resistant to ischaemia there are nevertheless many syndromes in which they are affected, either separately or together. It is frequently difficult to distinguish the effects of arterial ischaemia from those of compression, which may operate through vascular occlusion, or, in the case of peripheral nerve, by mechanical deformation of nerve fibres. A great deal has been learned from experimental models, but not all of it is applicable to the complexity of human neuromuscular ischaemia which requires further study. Images Fig. 1 Fig. 2 Fig. 3a Fig. 3b Fig. 4 Fig. 5 Fig. 6a-6b Fig. 6c-6f PMID:269124

  8. Shrapnel injury of isolated third cranial nerve.

    PubMed

    Uluta?, Murat; Seçer, Mehmet

    2014-12-01

    Isolated third nerve palsy develops in numerous intracranial pathologies such as closed head trauma, tumor, and aneurysm. Isolated oculomotor nerve palsy caused by shrapnel injury is uncommon. After a penetrating intracranial shrapnel injury, our patient with oculomotor ophthalmoplegia underwent surgery. Microsurgery removed the shrapnel that was applying pressure on the third nerve, resulting in contusion. A partial recovery associated with regeneration was observed at month 9. Extraocular muscle surgery should be planned if palsy does not resolve over a prolonged period of time. PMID:25485217

  9. Dynamic Changes in the MicroRNA Expression Profile Reveal Multiple Regulatory Mechanisms in the Spinal Nerve Ligation Model of Neuropathic Pain

    Microsoft Academic Search

    David von Schack; Michael J. Agostino; B. Stuart Murray; Yizheng Li; Padmalatha S. Reddy; Jin Chen; Sung E. Choe; Brian W. Strassle; Christine Li; Brian Bates; Lynn Zhang; Huijuan Hu; Smita Kotnis; Brendan Bingham; Wei Liu; Garth T. Whiteside; Tarek A. Samad; Jeffrey D. Kennedy; Seena K. Ajit; Maria Castro

    2011-01-01

    Neuropathic pain resulting from nerve lesions or dysfunction represents one of the most challenging neurological diseases to treat. A better understanding of the molecular mechanisms responsible for causing these maladaptive responses can help develop novel therapeutic strategies and biomarkers for neuropathic pain. We performed a miRNA expression profiling study of dorsal root ganglion (DRG) tissue from rats four weeks post

  10. Axonal accumulation of hyperpolarization-activated cyclic nucleotide-gated cation channels contributes to mechanical allodynia after peripheral nerve injury in rat

    Microsoft Academic Search

    Yu-Qiu Jiang; Guo-Gang Xing; Sheng-Lan Wang; Hui-Yin Tu; Ye-Nan Chi; Jie Li; Feng-Yu Liu; Ji-Sheng Han; You Wan

    2008-01-01

    Peripheral nerve injury causes neuropathic pain including mechanical allodynia and thermal hyperalgesia due to central and peripheral sensitization. Spontaneous ectopic discharges derived from dorsal root ganglion (DRG) neurons and from the sites of injury are a key factor in the initiation of this sensitization. Numerous studies have focused primarily on DRG neurons; however, the injured axons themselves likely play an

  11. Schwann Cell Engraftment Into Injured Peripheral Nerve Prevents Changes in Action Potential Properties

    PubMed Central

    Yu, Kewei; Kocsis, Jeffery D.

    2008-01-01

    Peripheral nerve injury results in changes in action potential waveform, ion channel organization, and firing properties of primary afferent neurons. It has been suggested that these changes are the result of reduction in basal trophic support from skin targets. Subcutaneous injections of Fluro-Gold (FG) in the hind limb of the rat were used to identify cutaneous primary afferent neurons. Five days after FG injection, sciatic nerves were ligated and encapsulated in a silicon tube allowing neuroma formation. Green fluorescent protein (GFP)-expressing Schwann cells (SCs) were injected proximal to the cut end of the nerve. Thirteen to 22 days after injury and SC injection, the L4 and L5 dorsal root ganglia (DRG) were prepared for acute culture. Whole cell patch-clamp recordings in current clamp mode were obtained and action potential properties of medium-sized (34–45 ?m) FG+ DRG neurons were characterized. In the neuroma group without cell transplantation, action potential duration and spike inflections were reduced as were the amplitude and duration of spike afterhyperpolarizations. These changes were not observed after transection by nerve crush where axons were allowed to regenerate to distal peripheral targets. In the transplantation group, GFP+-SCs were extensively distributed throughout the neuroma, and oriented longitudinally along axons proximal to the neuroma. Changes in action potential properties were attenuated in the GFP+-SC group. Thus the engrafted SC procedure ameliorated the changes in action potential waveform of cutaneous primary afferents associated with target disconnection and neuroma formation. PMID:16061494

  12. Microengineered peripheral nerve-on-a-chip for preclinical physiological testing.

    PubMed

    Huval, Renee M; Miller, Oliver H; Curley, J Lowry; Fan, Yuwei; Hall, Benjamin J; Moore, Michael J

    2015-05-01

    The use of advanced in vitro testing is a powerful tool to develop predictive cellular assays suitable for improving the high attrition rates of novel pharmaceutical compounds. A microscale, organotypic model of nerve tissue with physiological measures that mimic clinical nerve compound action potential (CAP) and nerve fiber density (NFD) tests may be more predictive of clinical outcomes, enabling a more cost-effective approach for selecting promising lead compounds with higher chances of late-stage success. However, the neurological architecture, physiology, and surrounding extracellular matrix are hard to mimic in vitro. Using a dual hydrogel construct and explants from rat embryonic dorsal root ganglia, the present study describes an in vitro method for electrophysiological recording of intra- and extra-cellular recordings using a spatially-controlled, microengineered sensory neural fiber tract. Specifically, these 3D neural cultures exhibit both structural and functional characteristics that closely mimic those of afferent sensory peripheral fibers found in vivo. Our dual hydrogel system spatially confines growth to geometries resembling nerve fiber tracts, allowing for a high density of parallel, fasciculated neural growth. Perhaps more importantly, outputs resembling clinically relevant test criteria, including the measurement of CAP and NFD are possible through our advanced model. Moreover, the 3D hydrogel constructs allow flexibility in incorporated cell type, geometric fabrication, and electrical manipulation, providing a viable assay for systematic culture, perturbation, and testing of biomimetic neural growth for mechanistic studies necessitating physiologically-relevant readouts. PMID:25850799

  13. Multichanneled collagen conduits for peripheral nerve regeneration: design, fabrication, and characterization.

    PubMed

    Yao, Li; Billiar, Kristen L; Windebank, Anthony J; Pandit, Abhay

    2010-12-01

    In the absence of donor tissues, conduits are needed for axons to regenerate across nerve defects, yet single-channel conduits may result in axonal dispersion, and multichannel synthetic polymer conduits have failed due to dimensional instability. The goal of this study was to create a robust collagen-based nerve conduit with multiple submillimeter-diameter channels to facilitate nerve guidance. Toward this goal, we have developed a novel multistep molding technique to create single-, four-, and seven-channel conduits from collagen and examined the effects of crosslinking with 0-60 mM (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide [EDC] in N-hydroxysuccinimide) on geometric, enzymatic, and thermal stability, mechanical properties, and cellular behavior. Multichannel collagen conduits crosslinked with 30 mM EDC and 10 mM N-hydroxysuccinimide demonstrated low degradation rate (?10% at 2 days), high shrinkage temperature (>75°C), and constant channel morphology out to 30 days in saline. Neurite outgrowth remained unaffected from cultured dorsal root ganglia explants seeded on collagen scaffolds with up to 30 mM EDC crosslinking. Compared with single-channel conduits, multichannel collagen conduits showed superior structural compressive, tensile, and bending stiffness. Taken together, these results suggest that the crosslinked multichannel collagen conduits possess favorable material and mechanical properties for nerve regeneration applications. PMID:20528663

  14. An apolipoprotein E-mimetic stimulates axonal regeneration and remyelination after peripheral nerve injury.

    PubMed

    Li, Feng-Qiao; Fowler, Kenneth A; Neil, Jessica E; Colton, Carol A; Vitek, Michael P

    2010-07-01

    Elevated apolipoprotein E (apoE) synthesis within crushed sciatic nerves advocates that apoE could benefit axonal repair and reconstruction of axonal and myelin membranes. We created an apoE-mimetic peptide, COG112 (acetyl-RQIKIWFQNRRMKWKKCLRVRLASHLRKLRKRLL-amide), and found that postinjury treatment with COG112 significantly improved recovery of motor and sensory function following sciatic nerve crush in C57BL/6 mice. Morphometric analysis of injured sciatic nerves revealed that COG112 promoted axonal regrowth after 2 weeks of treatment. More strikingly, the thickness of myelin sheaths was increased by COG112 treatment. Consistent with these histological findings, COG112 potently elevated growth associated protein 43 (GAP-43) and peripheral myelin protein zero (P0), which are markers of axon regeneration and remyelination, respectively. Electron microscopic examination further suggested that the apoE-mimetic COG112 may increase clearance of myelin debris. Schwann cell uptake of cholesterol-containing low-density lipoprotein particles was selectively enhanced by COG112 treatment in a Schwann cell line S16. Moreover, COG112 significantly promoted axon elongation in primary dorsal root ganglion cultures from rat pups. Considering that cholesterol and lipids are needed for reconstructing myelin sheaths and axon extension, these data support a hypothesis where supplementation with exogenous apoE-mimetics such as COG112 may be a promising strategy for restoring lost functional and structural elements following nerve injury. PMID:20406857

  15. Peripheral Nerve Blocks Improve Analgesia After Total Knee Replacement Surgery

    Microsoft Academic Search

    Hugh W. Allen; Spencer S. Liu; Paul D. Ware; Craig S. Nairn; Brian D. Owens

    1998-01-01

    Total knee replacement (TKR) produces severe postop- erative pain. Peripheral nerve blocks can be used as an- algesic adjuncts for TKR, but the efficacy of femoral nerve blocks alone is controversial. The sciatic nerve innervates posterior regions of the knee; thus, perfor- mance of both sciatic and femoral nerve blocks may be necessary to improve analgesia after TKR. We per-

  16. Vagus nerve stimulation and magnet use: Optimizing benefits

    Microsoft Academic Search

    William O. Tatum IV; Sandra L. Helmers

    2009-01-01

    More than 10years ago, the vagus nerve stimulator became the first device approved by the Food and Drug Administration for use in persons with epilepsy. The vagus nerve stimulator has subsequently served to spearhead the concept of neurostimulation for seizures. Chronic intermittent electrical stimulation of the left vagus nerve is the foundation for vagus nerve stimulation, yet little is known

  17. Superior segmental optic nerve hypoplasia: The topless disc syndrome

    Microsoft Academic Search

    Joseph Sowka; Lori Vollmer; Sherrol Reynolds

    2008-01-01

    BackgroundOptic nerve hypoplasia is a well-known congenital maldevelopment presenting with an abnormally small optic nerve head occupying the central aspect of a normally sized chorioscleral canal. Characteristically, the optic nerve head is surrounded by scleral anlage with a “double ring sign.” Less commonly appreciated, however, is the fact that optic nerve hypoplasia may be sectorial rather than total and involving

  18. Emerging nanotechnology approaches in tissue engineering for peripheral nerve regeneration

    Microsoft Academic Search

    Carla Cunha; Silvia Panseri; Stefania Antonini

    2011-01-01

    Effective nerve regeneration and functional recovery subsequent to peripheral nerve injury is still a clinical challenge. Autologous nerve graft transplantation is a feasible treatment in several clinical cases, but it is limited by donor site morbidity and insufficient donor tissue, impairing complete functional recovery. Tissue engineering has introduced innovative approaches to promote and guide peripheral nerve regeneration by using biomimetic

  19. Tendon Transfers Part II: Transfers for Ulnar Nerve Palsy and Median Nerve Palsy

    PubMed Central

    Sammer, Douglas M.; Chung, Kevin C.

    2009-01-01

    Objectives After reading this article (part II of II), the participant should be able to: 1. Describe the anatomy and function of the median and ulnar nerves in the forearm and hand. 2. Describe the clinical deficits associated with injury to each nerve. 3. Describe the indications, benefits, and drawbacks for various tendon transfer procedures used to treat median and ulnar nerve palsy.4. Describe the treatment of combined nerve injuries. 5. Describe postoperative care and possible complications associated with these tendon transfer procedures. Summary This article discusses the use of tendon transfer procedures for treatment of median and ulnar nerve palsy as well as combined nerve palsies. Postoperative management and potential complications are also discussed. PMID:19730287

  20. Ganglioside promotes the bridging of sciatic nerve defects in cryopreserved peripheral nerve allografts.

    PubMed

    Wang, Yaodong; Liu, Yuguang; Liu, Qiang

    2014-10-15

    Previous studies have shown that exogenous gangliosides promote nervous system regeneration and synapse formation. In this study, 10 mm sciatic nerve segments from New Zealand rabbits were thawed from cryopreservation and were used for the repair of left sciatic nerve defects through allograft bridging. Three days later, 1 mL ganglioside solution (1 g/L) was subcutaneously injected into the right hind leg of rabbits. Compared with non-injected rats, muscle wet weight ratio was increased at 2-12 weeks after modeling. The quantity of myelinated fibers in regenerated sciatic nerve, myelin thickness and fiber diameter were elevated at 4-12 weeks after modeling. Sciatic nerve potential amplitude and conduction velocity were raised at 8 and 12 weeks, while conduction latencies were decreased at 12 weeks. Experimental findings indicate that ganglioside can promote the regeneration of sciatic nerve defects after repair with cryopreserved peripheral nerve allografts. PMID:25422644

  1. Selective Targeting of TRPV1 Expressing Sensory Nerve Terminals in the Spinal Cord for Long Lasting Analgesia

    PubMed Central

    Sikand, Parul; Parihar, Arti; Evans, M. Steven; Premkumar, Louis S.

    2009-01-01

    Chronic pain is a major clinical problem and opiates are often the only treatment, but they cause significant problems ranging from sedation to deadly respiratory depression. Resiniferatoxin (RTX), a potent agonist of Transient Receptor Potential Vanilloid 1 (TRPV1), causes a slow, sustained and irreversible activation of TRPV1 and increases the frequency of spontaneous excitatory postsynaptic currents, but causes significant depression of evoked EPSCs due to nerve terminal depolarization block. Intrathecal administration of RTX to rats in the short-term inhibits nociceptive synaptic transmission, and in the long-term causes a localized, selective ablation of TRPV1-expressing central sensory nerve terminals leading to long lasting analgesia in behavioral models. Since RTX actions are selective for central sensory nerve terminals, other efferent functions of dorsal root ganglion neurons can be preserved. Preventing nociceptive transmission at the level of the spinal cord can be a useful strategy to treat chronic, debilitating and intractable pain. PMID:19753113

  2. Novel biomechanical quantification methodology for lumbar intraforaminal spinal nerve adhesion in a laminectomy and disc injury rat model.

    PubMed

    Kulkarni, Vedant A; Massie, Jennifer B; Zauner, Florian; Murphy, Mark; Akeson, Wayne H

    2007-10-15

    Spinal nerve fibrosis following injury or surgical intervention may play an important role in the pathophysiology of chronic back pain. In this current study, we demonstrate the role of biomechanical quantification of lumbar intraforaminal spinal nerve adhesion and tethering in the analysis of the post-laminectomy condition and describe a direct methodology to make this measurement. Twenty age-matched Sprague-Dawley male rats were divided into operative and non-operative (control) groups. Operative animals underwent a bilateral L5-L6 laminectomy with right-side L5-6 disc injury, a post-laminectomy pain model previously published by this lab. At eight weeks, animals were sacrificed and the strength of adhesion of the L5 intraforaminal spinal nerve to surrounding structures was quantified using a novel biomechanical methodology. Operative animals were found to have a significantly greater load to displace the intact right L5 spinal nerve through the intervertebral foramen when compared to control animals. The findings show that the post-laminectomy condition creates quantifiable fibrosis of the spinal nerve to surrounding structures and supports the conclusion that this fibrosis may play a role in the post-laminectomy pain syndrome. PMID:17689664

  3. Clinical outcomes for Conduits and Scaffolds in peripheral nerve repair.

    PubMed

    Gerth, David J; Tashiro, Jun; Thaller, Seth R

    2015-02-16

    The gold standard of peripheral nerve repair is nerve autograft when tensionless repair is not possible. Use of nerve autograft has several shortcomings, however. These include limited availability of donor tissue, sacrifice of a functional nerve, and possible neuroma formation. In order to address these deficiencies, researchers have developed a variety of biomaterials available for repair of peripheral nerve gaps. We review the clinical studies published in the English literature detailing outcomes and reconstructive options. Regardless of the material used or the type of nerve repaired, outcomes are generally similar to nerve autograft in gaps less than 3 cm. New biomaterials currently under preclinical evaluation may provide improvements in outcomes. PMID:25685760

  4. A polylactic acid non-woven nerve conduit for facial nerve regeneration in rats.

    PubMed

    Matsumine, Hajime; Sasaki, Ryo; Yamato, Masayuki; Okano, Teruo; Sakurai, Hiroyuki

    2014-06-01

    This study developed a biodegradable nerve conduit with PLA non-woven fabric and evaluated its nerve regeneration-promoting effect. The buccal branch of the facial nerve of 8 week-old Lewis rats was exposed, and a 7 mm nerve defect was created. A nerve conduit made of either PLA non-woven fabric (mean fibre diameter 460 nm), or silicone tube filled with type I collagen gel, or an autologous nerve, was implanted into the nerve defect, and their nerve regenerative abilities were evaluated 13 weeks after the surgery. The number of myelinated neural fibres in the middle portion of the regenerated nerve was the highest for PLA tubes (mean?±?SD, 5051?±?2335), followed by autologous nerves (4233?±?590) and silicone tubes (1604?±?148). Axon diameter was significantly greater in the PLA tube group (5.17?±?1.69 µm) than in the silicone tube group (4.25?±?1.60 µm) and no significant difference was found between the PLA tube and autograft (5.53?±?1.93 µm) groups. Myelin thickness was greatest for the autograft group (0.65?±?0.24 µm), followed by the PLA tube (0.54?±?0.18 µm) and silicone tube (0.38?±?0.12 µm) groups, showing significant differences among the three groups. The PLA non-woven fabric tube, composed of randomly-connected PLA fibres, is porous and has a number of advantages, such as sufficient strength to maintain luminal structure. The tube has demonstrated a comparable ability to induce peripheral nerve regeneration following autologous nerve transplantation. PMID:22689468

  5. Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

    PubMed Central

    Iwase, T.; Takebayashi, T.; Tanimoto, K.; Terashima, Y.; Miyakawa, T.; Kobayashi, T.; Tohse, N.; Yamashita, T.

    2012-01-01

    Objectives In order to elucidate the influence of sympathetic nerves on lumbar radiculopathy, we investigated whether sympathectomy attenuated pain behaviour and altered the electrical properties of the dorsal root ganglion (DRG) neurons in a rat model of lumbar root constriction. Methods Sprague-Dawley rats were divided into three experimental groups. In the root constriction group, the left L5 spinal nerve root was ligated proximal to the DRG as a lumbar radiculopathy model. In the root constriction + sympathectomy group, sympathectomy was performed after the root constriction procedure. In the control group, no procedures were performed. In order to evaluate the pain relief effect of sympathectomy, behavioural analysis using mechanical and thermal stimulation was performed. In order to evaluate the excitability of the DRG neurons, we recorded action potentials of the isolated single DRG neuron by the whole-cell patch-clamp method. Results In behavioural analysis, sympathectomy attenuated the mechanical allodynia and thermal hyperalgesia caused by lumbar root constriction. In electrophysiological analysis, single isolated DRG neurons with root constriction exhibited lower threshold current, more depolarised resting membrane potential, prolonged action potential duration, and more depolarisation frequency. These hyperexcitable alterations caused by root constriction were significantly attenuated in rats treated with surgical sympathectomy. Conclusion The present results suggest that sympathectomy attenuates lumbar radicular pain resulting from root constriction by altering the electrical property of the DRG neuron itself. Thus, the sympathetic nervous system was closely associated with lumbar radicular pain, and suppressing the activity of the sympathetic nervous system may therefore lead to pain relief. PMID:23610691

  6. Topics In Primitive Roots

    E-print Network

    N. A. Carella

    2015-03-12

    This monograph considers a few topics in the theory of primitive roots g(p) modulo a prime p>=2. A few estimates of the least primitive roots g(p) and the least prime primitive roots g^*(p) modulo p, a large prime, are determined. One of the estimate here seems to sharpen the Burgess estimate g(p) 0, to the smaller estimate g(p) 2. The expected order of magnitude is g(p) 1 constant. The corresponding estimates for least prime primitive roots g^*(p) are slightly higher. Anotrher topic deals with an effective lower bound #{p > x/log x for the number of primes p 1. The current results in the literature claim the lower bound #{p > x/(log x)^2, and have restrictions on the minimal number of fixed integers to three or more.

  7. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...accordance with ASTM E 29-67. (2) For rotary engines, displacement means the maximum...

  8. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...reference in § 86.1). (2) For rotary engines, displacement means the maximum...

  9. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...reference in § 86.1). (2) For rotary engines, displacement means the maximum...

  10. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...accordance with ASTM E 29-67. (2) For rotary engines, displacement means the maximum...

  11. 40 CFR 86.419-78 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...accordance with ASTM E 29-67. (2) For rotary engines, displacement means the maximum...

  12. 40 CFR 86.419-2006 - Engine displacement, motorcycle classes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to the nearest whole...reference in § 86.1). (2) For rotary engines, displacement means the maximum...

  13. Scale model studies of displacement ventilation

    E-print Network

    Okutan, Galip Mehmet

    1995-01-01

    Displacement ventilation is an air conditioning method that provides conditioned air to indoor environments with the goal to improve air quality while reducing energy consumption. This study investigates the performance ...

  14. Seismic transducer measures small horizontal displacements

    NASA Technical Reports Server (NTRS)

    Greenwood, T. L.

    1965-01-01

    Pendular seismic transducer mounted on base plate measures small horizontal displacements of structures subjected to vibration where no fixed reference point is available. Enclosure of transducer in transparent plastic case prevents air currents from disturbing the pendulum balance.

  15. Chitooligosaccharides promote peripheral nerve regeneration in a rabbit common peroneal nerve crush injury model.

    PubMed

    Gong, Yanpei; Gong, Leilei; Gu, Xiaosong; Ding, Fei

    2009-01-01

    Chitooligosaccharides (COSs) are the biodegradation products of chitosan that have been demonstrated with neuroaffinity and/or neuroprotective actions. In this study, we investigated the possible benefits of treatment with COSs on nerve regeneration after crush injuries to peripheral nerves. The rabbits with the crushed common peroneal nerve were treated by daily intravenous injection of 1.5 or 3 mg/kg body weight of COSs or identical volume of saline (as the control) for a 6-week period. At the end of COSs treatment, electrophysiological assessments, Meyer's trichrome and Masson trichrome staining, and transmission electron microscopy were used to evaluate the regeneration of injured common peroneal nerve and atrophy of the tibialis posterior muscle. The results showed that the compound muscle action potentials, the number of regenerated myelinated nerve fibers, the thickness of regenerated myelin sheaths, and the cross-sectional area of tibialis posterior muscle fibers were significantly improved in the nerves that received COSs treatment and the results with COSs treatment displayed a dose-dependent pattern. This study demonstrated that COSs accelerated peripheral nerve regeneration after crush injury to rabbit common peroneal nerves. The COSs could probably become a potential neuroprotective agent for improvement of peripheral nerve regeneration after the injury and deserve for further studies. PMID:19653322

  16. Longitudinal Excursion and Strain in the Median Nerve during Novel Nerve Gliding Exercises for Carpal Tunnel Syndrome

    Microsoft Academic Search

    Michel W. Coppieters; Ali M. Alshami

    2006-01-01

    Nerve and tendon gliding exercises are advocated in the conservative and post- operative management of carpal tunnel syndrome (CTS). However, traditionally advocated exercises elongate the nerve bedding substantially, which may induce a potentially deleterious strain in the median nerve with the risk of symptom exacerbation in some patients and reduced benefits from nerve gliding. This study aimed to evaluate various

  17. POSTERIOR INTEROSSEOUS NERVE SYNDROME DUE TO PSEUDOGOUT

    Microsoft Academic Search

    Y. TANIGUCHI; M. YOSHIDA; T. TAMAKI

    1999-01-01

    Posterior interosseous nerve palsy associated with pseudogout of the elbow joint in a 71-year-old woman is described. Local steroid injection and administration of a nonsteroidal anti-inflammatory drug was effective in treatment.

  18. Vagus Nerve Stimulation for Treating Epilepsy

    MedlinePLUS

    ... and their FAMILIES VAGUS NERVE STIMULATION FOR TREATING EPILEPSY This information sheet is provided to help you ... apnea for people with the condition I HAVE EPILEPSY, AND MY CURRENT THERAPY IS NOT HELPING ME. ...

  19. Investigation of nerve injury through microfluidic devices

    PubMed Central

    Siddique, Rezina; Thakor, Nitish

    2014-01-01

    Traumatic injuries, both in the central nervous system (CNS) and peripheral nervous system (PNS), can potentially lead to irreversible damage resulting in permanent loss of function. Investigating the complex dynamics involved in these processes may elucidate the biological mechanisms of both nerve degeneration and regeneration, and may potentially lead to the development of new therapies for recovery. A scientific overview on the biological foundations of nerve injury is presented. Differences between nerve regeneration in the central and PNS are discussed. Advances in microtechnology over the past several years have led to the development of invaluable tools that now facilitate investigation of neurobiology at the cellular scale. Microfluidic devices are explored as a means to study nerve injury at the necessary simplification of the cellular level, including those devices aimed at both chemical and physical injury, as well as those that recreate the post-injury environment. PMID:24227311

  20. Specialized Nerve Tests: EMG, NCV and SSEP

    MedlinePLUS

    ... spinal cord are able to send and receive sensory information like pain, temperature and touch. When ordering ... SSEP is used to double check whether the sensory part of the nerve is working correctly. What ...

  1. 'Skinny Jeans' Linked to Woman's Nerve Damage

    MedlinePLUS

    ... nlm.nih.gov/medlineplus/news/fullstory_153208.html 'Skinny Jeans' Linked to Woman's Nerve Damage After spending ... emptying cupboards. She said she was wearing tight "skinny" jeans that became increasingly uncomfortable as the day ...

  2. Vagal nerve stimulation does not unkindle seizures.

    PubMed

    Dasheiff, R M; Sandberg, T; Thompson, J; Arrambide, S

    2001-01-01

    The purpose of this study was to investigate a mechanism of action for the effect of vagal nerve stimulation on reducing seizures in patients with complex partial epilepsy. The hypothesis tested was that vagal nerve stimulation has an antikindling effect on epilepsy. The databases of two large clinical trials (E03, E05) were accessed, and statistical methods were applied using logarithmic transforms and regression analysis. Two parameters--duration of a patient's epilepsy before entering the clinical trial and the patient's seizure density before entering the clinical trial--were used as markers of subsequent seizure control during vagal nerve stimulation. In general, there was not a good fit to the regression lines, and the slope of the lines did not conform to the hypothesis. The hypothesis that vagal nerve stimulation may unkindle epileptic seizures was not supported. PMID:11290941

  3. New developments with vagus nerve stimulation therapy.

    PubMed

    Howland, Robert H

    2014-03-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuro-endocrine-immune axis. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve. Left cervical VNS is an approved therapy for refractory epilepsy and treatment-resistant depression. Right cervical VNS has proven effective for treating heart failure in preclinical studies and a Phase II clinical trial. The effectiveness of noninvasive transcutaneous VNS for epilepsy, depression, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, and cardiovascular, cerebrovascular, and metabolic syndromes might be mediated by the vagus nerve. Transcutaneous VNS deserves further study as an antidepressant therapy and for its potential effect on physiological biomarkers associated with depression morbidity and mortality. PMID:24745061

  4. Cotton Root-rot. 

    E-print Network

    Pammel, L. H. (Louis Herman)

    1889-01-01

    121 2 -16 1 t I i 6' /t AS AGRICULTURAL EXY ERIMENT STATI( BULLETIN No. 7, C. NOVEMBER, 1889. COTTON ROOT-ROT AGRICULTURAL AND MECHANICAL COLLEGE, College Station, Brazos County, Texas. BY ORDER OF THE COUNCIL: F. A. GULLEY, DIRECTOR..... ....................... .Assistant to Director. D. ADRIANCE .......................... Asst. Chemist and Meteorologist. J. M. Ca~son. ........................ .Assistant to Agriculturist. C. K. FUQUA.. ........................ .Sugar Chemist. COTTON ROOT-ROT. sout It =ng...

  5. Interferometer for measuring displacement and distance

    Microsoft Academic Search

    Toshihiro Kubota; Makoto Nara; Toshihiko Yoshino

    1987-01-01

    A simple interferometer for measuring both relative displacement and absolute distance is fabricated that uses a laser diode. The sign of the displacementis detected by means of a lambda\\/8 plate, and the distance is measured by an FM radar technique of modulating the laser-diode frequency. Measurement accuracies of 0.02 micron for displacement and 100 microns for distance are obtained over

  6. Treatment of traumatic infra orbital nerve paresthesia.

    PubMed

    Lone, Parveen Akhter; Singh, R K; Pal, U S

    2012-07-01

    This study was done to find out the role of topiramate therapy in infraorbital nerve paresthesia after miniplate fixation in zygomatic complxex fractures. A total 2 cases of unilateral zygomatic complex fracture, 2-3 weeks old with infra orbital nerve paresthesia were slected. Open reduction and plating was done in frontozygomaticregion. Antiepileptic drug tab topiramate was given in therapeutic doses and dose was increased slowly until functional recovery was noticed. PMID:23833503

  7. Malignant peripheral nerve sheath tumor of mandible.

    PubMed

    Zakhary, Ibrahim; Elsalanty, Mohammed; Ishag, Ilia; Taher, Taher; Hassan, Mohammed; Gehani, Rafi; Orafi, Marai; El-Mekkawi, Hatem

    2011-03-01

    Malignant peripheral nerve sheath tumor is a common tumor that rarely affects the head and neck region. The patient presented in this report is a teenage girl presented with a lesion in the right body of the mandible with severe disfigurement of the lower face. The lesion was first histopathologically diagnosed as embryonal rhabdomyosarcoma. After excision, however, the histopathology report proved the diagnosis of malignant peripheral nerve sheath tumor. PMID:21415661

  8. Congenital cystic eye with optic nerve.

    PubMed

    Holland, Lee; Haridas, Anjana; Phillips, Gael; Sullivan, Timothy

    2015-01-01

    Congenital cystic eye (CCE) is a rare condition caused by failure of invagination of the optic vesicle resulting in a persistent cyst replacing the eye. An associated optic nerve attached to the cyst is a rarely reported phenomenon that has been sparsely described histologically, with no immunohistochemistry reported previously. The authors present a case of CCE with optic nerve tissue inserting into the cyst, and present the histological and immunohistochemical findings. PMID:26178229

  9. Substance P in the vagus nerve

    Microsoft Academic Search

    R. Gamse; F. Lembeck; A. C. Cuello

    1979-01-01

    1.The presence of immunoreactive substance P (I-SP) in the vagus nerve of 5 species was demonstrated by radioimmunoassay. Different amounts of SP per unit weight were found: Guinea pig > cat > rabbit, rat and cattle.2.Infranodose ligations of the vagus nerve of cats and rabbits caused an accumulation of I-SP proximal but not distal to the ligation. The results obtained

  10. PDT - PARTICLE DISPLACEMENT TRACKING SOFTWARE

    NASA Technical Reports Server (NTRS)

    Wernet, M. P.

    1994-01-01

    Particle Imaging Velocimetry (PIV) is a quantitative velocity measurement technique for measuring instantaneous planar cross sections of a flow field. The technique offers very high precision (1%) directionally resolved velocity vector estimates, but its use has been limited by high equipment costs and complexity of operation. Particle Displacement Tracking (PDT) is an all-electronic PIV data acquisition and reduction procedure which is simple, fast, and easily implemented. The procedure uses a low power, continuous wave laser and a Charged Coupled Device (CCD) camera to electronically record the particle images. A frame grabber board in a PC is used for data acquisition and reduction processing. PDT eliminates the need for photographic processing, system costs are moderately low, and reduced data are available within seconds of acquisition. The technique results in velocity estimate accuracies on the order of 5%. The software is fully menu-driven from the acquisition to the reduction and analysis of the data. Options are available to acquire a single image or 5- or 25-field series of images separated in time by multiples of 1/60 second. The user may process each image, specifying its boundaries to remove unwanted glare from the periphery and adjusting its background level to clearly resolve the particle images. Data reduction routines determine the particle image centroids and create time history files. PDT then identifies the velocity vectors which describe the particle movement in the flow field. Graphical data analysis routines are included which allow the user to graph the time history files and display the velocity vector maps, interpolated velocity vector grids, iso-velocity vector contours, and flow streamlines. The PDT data processing software is written in FORTRAN 77 and the data acquisition routine is written in C-Language for 80386-based IBM PC compatibles running MS-DOS v3.0 or higher. Machine requirements include 4 MB RAM (3 MB Extended), a single or multiple frequency RGB monitor (EGA or better), a math co-processor, and a pointing device. The printers supported by the graphical analysis routines are the HP Laserjet+, Series II, and Series III with at least 1.5 MB memory. The data acquisition routines require the EPIX 4-MEG video board and optional 12.5MHz oscillator, and associated EPIX software. Data can be acquired from any CCD or RS-170 compatible video camera with pixel resolution of 600hX400v or better. PDT is distributed on one 5.25 inch 360K MS-DOS format diskette. Due to the use of required proprietary software, executable code is not provided on the distribution media. Compiling the source code requires the Microsoft C v5.1 compiler, Microsoft QuickC v2.0, the Microsoft Mouse Library, EPIX Image Processing Libraries, the Microway NDP-Fortran-386 v2.1 compiler, and the Media Cybernetics HALO Professional Graphics Kernal System. Due to the complexities of the machine requirements, COSMIC strongly recommends the purchase and review of the documentation prior to the purchase of the program. The source code, and sample input and output files are provided in PKZIP format; the PKUNZIP utility is included. PDT was developed in 1990. All trade names used are the property of their respective corporate owners.

  11. Displacement sensor for indoor machine calibrations.

    PubMed

    Mudassar, Asloob Ahmad; Butt, Saira

    2013-05-20

    This paper presents a simple displacement sensor for indoor machine calibrations. The sensor, which is placed in the path of a diverging laser beam, consists of two plane mirror pieces laterally displaced with the line joining their centers initially held perpendicular to the optical axis of the beam during the displacement of the sensor with one of the mirrors always traveling along the optical axis of the laser beam. The optical signals from the two mirrors are combined and a simple detector at the interference plane counts the fringes during the sensor displacement. The sensor could be mounted on the moving head of any mechanical machine, e.g., the lathe machine for displacement calibration. The device has been tested over a range of 10 cm beyond a distance of 150 cm from a diverging laser source giving an accuracy of 1.1015 ?m. Theoretical modeling, simulation, and experimental results are presented which establish that the proposed sensor can be used as a promising displacement measuring device. PMID:23736230

  12. Soil Penetration by Earthworms and Plant Roots—Mechanical Energetics of Bioturbation of Compacted Soils

    PubMed Central

    2015-01-01

    We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip). The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities. PMID:26087130

  13. Rapid repair and regeneration of damaged rabbit sciatic nerves by tissue-engineered scaffold made from nano-silver and collagen type I.

    PubMed

    Ding, Tan; Luo, Zhuo-Jing; Zheng, Yan; Hu, Xue-Yu; Ye, Zheng-Xu

    2010-05-01

    A tissue-engineered scaffold with nano-silver and collagen type I was constructed and investigated for its ability to adsorb laminin and the usefulness in the repair and regeneration of damaged peripheral nerves in animals. The nano-silver scaffold displayed ideal microtubule structure under electronic microscope; even distribution of the nano-silver particles was also seen with energy spectrometry. After immersion in a laminin solution, the laminin-attached scaffolds were implanted into rabbits to repair a 10-mm injury of the sciatic nerve. At 30 days post-implantation, regeneration of the damaged nerve was evaluated by transmission electron microscopy, electrophysiological examination and fluoro-gold (FG) retrograde labelling. Compared with the control collagen-scaffold without nano-silver, the nano-silver-containing scaffold showed a higher rate of laminin adsorption, regenerated a nerve with a thicker myelin sheath and improved the nerve conduction velocity and nerve potential amplitude. FG retrograde labelled the newly grown axons in the spinal cord cortex anterior horn and the dorsal root ganglion. These results demonstrate the superior functionality of the nano-silver-collagen scaffold in the adsorption to laminin and subsequent regeneration of damaged peripheral nerves. PMID:19524233

  14. Peripheral nerve stimulation in chronic cluster headache.

    PubMed

    Magis, Delphine; Schoenen, Jean

    2011-01-01

    Cluster headache is well known as one of the most painful primary neurovascular headache. Since 1% of chronic cluster headache patients become refractory to all existing pharmacological treatments, various invasive and sometimes mutilating procedures have been tempted in the last decades. Recently, neurostimulation methods have raised new hope for drug-resistant chronic cluster headache patients. The main focus of this chapter is on stimulation of the great occipital nerve, which has been the best evaluated peripheral nerve stimulation technique in drug-resistant chronic cluster headache, providing the most convincing results so far. Other peripheral nerve stimulation approaches used for this indication are also reviewed in detail. Although available studies are limited to a relatively small number of patients and placebo-controlled trials are lacking, existent clinical data suggest that occipital nerve stimulation should nonetheless be recommended for intractable chronic cluster headache patients before more invasive deep brain stimulation surgery. More studies are needed to evaluate the usefulness of supraorbital nerve stimulation and of vagus nerve stimulation in management of cluster headaches. PMID:21422783

  15. Brain imaging correlates of peripheral nerve stimulation

    PubMed Central

    Bari, Ausaf A.; Pouratian, Nader

    2012-01-01

    Direct peripheral nerve stimulation is an effective treatment for a number of disorders including epilepsy, depression, neuropathic pain, cluster headache, and urological dysfunction. The efficacy of this stimulation is ultimately due to modulation of activity in the central nervous system. However, the exact brain regions involved in each disorder and how they are modulated by peripheral nerve stimulation is not fully understood. The use of functional neuroimaging such as SPECT, PET and fMRI in patients undergoing peripheral nerve stimulation can help us to understand these mechanisms. We review the literature for functional neuroimaging performed in patients implanted with peripheral nerve stimulators for the above-mentioned disorders. These studies suggest that brain activity in response to peripheral nerve stimulation is a complex interaction between the stimulation parameters, disease type and severity, chronicity of stimulation, as well as nonspecific effects. From this information we may be able to understand which brain structures are involved in the mechanism of peripheral nerve stimulation as well as define the neural substrates underlying these disorders. PMID:23230531

  16. Root architecture impacts on root decomposition rates in switchgrass

    NASA Astrophysics Data System (ADS)

    de Graaff, M.; Schadt, C.; Garten, C. T.; Jastrow, J. D.; Phillips, J.; Wullschleger, S. D.

    2010-12-01

    Roots strongly contribute to soil organic carbon accrual, but the rate of soil carbon input via root litter decomposition is still uncertain. Root systems are built up of roots with a variety of different diameter size classes, ranging from very fine to very coarse roots. Since fine roots have low C:N ratios and coarse roots have high C:N ratios, root systems are heterogeneous in quality, spanning a range of different C:N ratios. Litter decomposition rates are generally well predicted by litter C:N ratios, thus decomposition of roots may be controlled by the relative abundance of fine versus coarse roots. With this study we asked how root architecture (i.e. the relative abundance of fine versus coarse roots) affects the decomposition of roots systems in the biofuels crop switchgrass (Panicum virgatum L.). To understand how root architecture affects root decomposition rates, we collected roots from eight switchgrass cultivars (Alamo, Kanlow, Carthage, Cave-in-Rock, Forestburg, Southlow, Sunburst, Blackwell), grown at FermiLab (IL), by taking 4.8-cm diameter soil cores from on top of the crown and directly next to the crown of individual plants. Roots were carefully excised from the cores by washing and analyzed for root diameter size class distribution using WinRhizo. Subsequently, root systems of each of the plants (4 replicates per cultivar) were separated in 'fine' (0-0.5 mm), 'medium' (0.5-1 mm) and 'coarse' roots (1-2.5 mm), dried, cut into 0.5 cm (medium and coarse roots) and 2 mm pieces (fine roots), and incubated for 90 days. For each of the cultivars we established five root-treatments: 20g of soil was amended with 0.2g of (1) fine roots, (2) medium roots, (3) coarse roots, (4) a 1:1:1 mixture of fine, medium and coarse roots, and (5) a mixture combining fine, medium and coarse roots in realistic proportions. We measured CO2 respiration at days 1, 3, 7, 15, 30, 60 and 90 during the experiment. The 13C signature of the soil was -26‰, and the 13C signature of plants was -12‰, enabling us to differentiate between root-derived C and native SOM-C respiration. We found that the relative abundance of fine, medium and coarse roots were significantly different among cultivars. Root systems of Alamo, Kanlow and Cave-in-Rock were characterized by a large abundance of coarse-, relative to fine roots, whereas Carthage, Forestburg and Blackwell had a large abundance of fine, relative to coarse roots. Fine roots had a 28% lower C:N ratio than medium and coarse roots. These differences led to different root decomposition rates. We conclude that root architecture should be taken into account when predicting root decomposition rates; enhanced understanding of the mechanisms of root decomposition will improve model predictions of C input to soil organic matter.

  17. Glial Cell Line-Derived Neurotrophic Factor Alters Axon Schwann Cell Units and Promotes Myelination in Unmyelinated Nerve Fibers

    Microsoft Academic Search

    Ahmet Hoke; Tony Ho; Thomas O. Crawford; Carl LeBel; Dana Hilt; John W. Griffin

    2003-01-01

    Glial cell line-derived neurotrophic factor (GDNF) plays an important role in the development and maintenance of a subset of dorsal root ganglion sensory neurons. We administered high-dose exogenous recombinant human GDNF (rhGDNF) daily to adult rats to examine its effect on unmyelinated axon-Schwann cell units in intact peripheral nerves. In rhGDNF-treated animals, there was a dramatic prolifer- ation in the

  18. Treating root-surface caries

    Microsoft Academic Search

    John O. Burgess; John R. Gallo

    2002-01-01

    Gingival recession associated with aging and periodontal therapy exposes root surfaces, which are then susceptible to root caries. Resin-modified glass ionomer, glass ionomer, compomer, composite resin, and amalgam restora- tive materials are frequently used to restore carious root lesions. Amalgam continues to be used successfully to restore root caries. Resin composites, compomers, glass ionomers, and resin-modified glass ionomers are increas-

  19. The "Green" Root Beer Laboratory

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  20. [Iatrogenic injury of peripheral nerves].

    PubMed

    Horiuchi, Yukio

    2014-12-01

    There are many risks of iatrogenic peripheral-nerve injuries during routine medical procedures. These injuries may occur during venipuncture for drawing blood, endoscopic treatments, punctures of joints or ganglions, various kinds of surgical procedures, and in numerous other situations. It is important to create a "Manual" of such accidents or incidents. In case an accident occurs, both the medical staff and the injured patient should receive adequate support to avoid any anxiety. The doctor must examine the person's injury carefully, and must judge its severity as soon as possible. The doctor must also offer the patient a prompt explanation about their injury and its proper care or treatment. This explanation must be easy to understand. This step can reduce patient anxiety and even prevent the early stages of complex regional pain syndrome (CRPS). One of my therapeutic strategies for treating early-stage CRPS is to use prednisolone for a short period for the treatment of strong pain and serious edema; the other approach is to do administer a warm-cold alternating bath with range-of-motion (ROM) exercise. Creation of manuals and education of staff to quickly respond to such situations is extremely essential. PMID:25475033